COLOMBO, Sri Lanka — The prime minister of Sri Lanka, Mahinda Rajapaksa, resigned Monday following weeks of protests demanding that he and his brother, the president, step down for dragging the country into its worst economic crisis in decades.

Prime Minister Rajapaksa said on Twitter that he submitted his resignation to his brother, President Gotabaya Rajapaksa, a move that followed a violent attack by government supporters on the protesters, prompting authorities to deploy armed troops in the capital, Colombo. There was no immediate comment from the president’s office.

For more than a month, protests have spread across the country, drawing people across ethnicities, religions, and classes. For the first time middle-class Sri Lankans also took to the streets in large numbers, marking a dramatic revolt by many former Rajapaksa supporters, some of whom have spent weeks protesting outside the president’s office.

The protests have sparked a political reckoning, with the government facing a no-confidence motion in Parliament, and underscored a dramatic fall from favor of the Rajapaksas, Sri Lanka’s most powerful political dynasty for decades. The brothers were once hailed as heroes by many of the island’s Buddhist-Sinhalese majority for ending the country’s 30-year civil war, and despite accusations of war atrocities, the two were firmly entrenched at the top of Sri Lankan politics until now.

The prime minister’s resignation comes as the country’s economy has swiftly unraveled in recent weeks, causing extraordinary pain to Sri Lankans. Imports of everything from milk to fuel have plunged, spawning dire food shortages and rolling power cuts. People have been forced to stand in lines for hours to buy essentials. Doctors have warned of a crippling shortage of life-saving drugs in hospitals, and the government has suspended payments on $7 billion in foreign debt due this year alone.

President Gotabaya Rajapaksa initially blamed global factors for Sri Lanka’s economic woes, like the pandemic battering its tourism industry and the Russia-Ukraine conflict pushing up global oil prices. Both he and his brother have since admitted to mistakes that exacerbated the crisis, including conceding that they should have sought an International Monetary Fund bailout sooner.

Sri Lanka has been holding talks with the IMF to set up a rescue plan but its progress depends on negotiations on debt restructuring with creditors. Any long-term plan would take at least six months to get underway.

Sri Lanka was in financial trouble even before the Ukraine war drove up food prices and made things worse.

The Sri Lankan government has been running big budget deficits after cutting taxes in 2019 and struggling to collect taxes during the COVID-19 pandemic. It also has piled up massive foreign debt — much of it owed to China — and has scant foreign exchange reserves to pay for imports and to defend its embattled currency, the rupee.

Sri Lanka is at the top of a list compiled by Liliana Rojas-Suarez of the Center for Global Development that ranks the countries most exposed to financial shocks. Those most vulnerable rely on commodity imports and have low foreign exchange reserves compared to what they owe other countries.

Monday’s violence triggered widespread anger, with people singling out Rajapaksa supporters and attacking them in many parts of the country. Homes of some government ministers and politicians supporting the Rajapaksas were also attacked and some set on fire.

A veteran political scientist at Colombo, Jayadeva Uyangoda, said the prime minister’s resignation was “a very significant development” and marked a new chapter in the country’s political crisis. “The prime minister had to resign in disgrace after his supporters unleashed such violence,” he said.

He added that it was an extremely serious setback for the Rajapaksas and would be difficult for the president to maintain credibility after the attack.

But the president has so far refused to resign and Parliament must go through a difficult process if it attempts to oust him. The resignation of the prime minister means that the entire Cabinet is dissolved.

Earlier on Monday, the prime minister’s supporters attacked protesters who had been demonstrating outside the prime minister’s official residence for weeks, hitting them with wooden and iron poles. They then marched to the president’s office, where they attacked protesters there and set their camps on fire.

Police fired tear gas and a water cannon at the protest site, but not forcefully enough to control the mob.

The attack occurred despite a state of emergency declared by the president Friday that gave him wide powers for riot control.

Hundreds of armed soldiers were deployed in the capital, as the protesters accused police of not preventing the attack, despite using tear gas and water cannons on protesters on Friday.

“Police did not protect us, therefore we have taken it into our own hands,” said Druvi Jinasena, who was helping block roads to protect the protest site.

An official at the main hospital at Colombo said 173 people were treated, most for minor injuries, though 15 were seriously injured. The official spoke on condition of anonymity because she was not authorized to speak to the media.

The country’s foreign reserves have plummeted below $50 million and it owes nearly $25 billion in foreign debt for payment by 2026. Its total foreign debt is $51 billion.

Meanwhile, popular anger at the Rajapaksa clan has only grown. Observers say the resignation and the violence ramps up pressure on President Gotabaya Rajapaksa to quit too.

“There has been sustained pressure for the last several weeks for the president to resign but he hasn’t paid much attention to that,” said a senior researcher at the Colombo-based Center for Policy Alternatives, Bhavani Fonsek.

“The site outside his office has seen among the largest protests but he still hasn’t addressed the elephant in the room — that of his own resignation,” she added.

“People are furious — and that anger is not going away anytime soon.”

For more than a month, protests have spread across the country, drawing people across ethnicities, religions, and classes. For the first time middle-class Sri Lankans also took to the streets in large numbers, marking a dramatic revolt by many former Rajapaksa supporters, some of whom have spent weeks protesting outside the president’s office.

The protests have sparked a political reckoning, with the government facing a no-confidence motion in Parliament, and underscored a dramatic fall from favor of the Rajapaksas, Sri Lanka’s most powerful political dynasty for decades. The brothers were once hailed as heroes by many of the island’s Buddhist-Sinhalese majority for ending the country’s 30-year civil war, and despite accusations of war atrocities, the two were firmly entrenched at the top of Sri Lankan politics until now.

The prime minister’s resignation comes as the country’s economy has swiftly unraveled in recent weeks, causing extraordinary pain to Sri Lankans. Imports of everything from milk to fuel have plunged, spawning dire food shortages and rolling power cuts. People have been forced to stand in lines for hours to buy essentials. Doctors have warned of a crippling shortage of life-saving drugs in hospitals, and the government has suspended payments on $7 billion in foreign debt due this year alone.

President Gotabaya Rajapaksa initially blamed global factors for Sri Lanka’s economic woes, like the pandemic battering its tourism industry and the Russia-Ukraine conflict pushing up global oil prices. Both he and his brother have since admitted to mistakes that exacerbated the crisis, including conceding that they should have sought an International Monetary Fund bailout sooner.

Sri Lanka has been holding talks with the IMF to set up a rescue plan but its progress depends on negotiations on debt restructuring with creditors. Any long-term plan would take at least six months to get underway.

Sri Lanka was in financial trouble even before the Ukraine war drove up food prices and made things worse.

The Sri Lankan government has been running big budget deficits after cutting taxes in 2019 and struggling to collect taxes during the COVID-19 pandemic. It also has piled up massive foreign debt — much of it owed to China — and has scant foreign exchange reserves to pay for imports and to defend its embattled currency, the rupee.

Sri Lanka is at the top of a list compiled by Liliana Rojas-Suarez of the Center for Global Development that ranks the countries most exposed to financial shocks. Those most vulnerable rely on commodity imports and have low foreign exchange reserves compared to what they owe other countries.

Monday’s violence triggered widespread anger, with people singling out Rajapaksa supporters and attacking them in many parts of the country. Homes of some government ministers and politicians supporting the Rajapaksas were also attacked and some set on fire.

A veteran political scientist at Colombo, Jayadeva Uyangoda, said the prime minister’s resignation was “a very significant development” and marked a new chapter in the country’s political crisis. “The prime minister had to resign in disgrace after his supporters unleashed such violence,” he said.

He added that it was an extremely serious setback for the Rajapaksas and would be difficult for the president to maintain credibility after the attack.

But the president has so far refused to resign and Parliament must go through a difficult process if it attempts to oust him. The resignation of the prime minister means that the entire Cabinet is dissolved.

Earlier on Monday, the prime minister’s supporters attacked protesters who had been demonstrating outside the prime minister’s official residence for weeks, hitting them with wooden and iron poles. They then marched to the president’s office, where they attacked protesters there and set their camps on fire.

Police fired tear gas and a water cannon at the protest site, but not forcefully enough to control the mob.

The attack occurred despite a state of emergency declared by the president Friday that gave him wide powers for riot control.

Hundreds of armed soldiers were deployed in the capital, as the protesters accused police of not preventing the attack, despite using tear gas and water cannons on protesters on Friday.

“Police did not protect us, therefore we have taken it into our own hands,” said Druvi Jinasena, who was helping block roads to protect the protest site.

An official at the main hospital at Colombo said 173 people were treated, most for minor injuries, though 15 were seriously injured. The official spoke on condition of anonymity because she was not authorized to speak to the media.

The country’s foreign reserves have plummeted below $50 million and it owes nearly $25 billion in foreign debt for payment by 2026. Its total foreign debt is $51 billion.

Meanwhile, popular anger at the Rajapaksa clan has only grown. Observers say the resignation and the violence ramps up pressure on President Gotabaya Rajapaksa to quit too.

“There has been sustained pressure for the last several weeks for the president to resign but he hasn’t paid much attention to that,” said a senior researcher at the Colombo-based Center for Policy Alternatives, Bhavani Fonsek.

“The site outside his office has seen among the largest protests but he still hasn’t addressed the elephant in the room — that of his own resignation,” she added.

“People are furious — and that anger is not going away anytime soon.”