KABUL, Afghanistan — Dozens of Afghans clutching numbered gold tokens line up every day outside the Indian Embassy, hoping to secure a visa to New Delhi. When embassy convoys enter the compound, guards grab their guns and yell at bystanders to get out of the way.

Today, a suicide car bomber made clear why those precautions were needed.

A suicide bomber following a diplomat’s vehicle detonated a load of explosives at the embassy gates, sending burning metal into dozens of Afghans standing in line, and into scores more walking the tree-lined street. Women and children were among the victims who lay on the ground, bloodied and in agony, crying for help.

The blast killed 41 people and wounded nearly 150 others, scattering bodies and pools of blood across some of Kabul’s most protected streets.

As in other recent high-profile attacks, Afghanistan quickly blamed Pakistan, India’s archrival, for the blast, which was the deadliest in Kabul since the fall of the Taliban in 2001.

The bomb detonated only 30 yards from where dozens of Afghans wait to apply for visas, one of the reasons the casualties were so high.

The embassy is on a busy street near Afghanistan’s Interior Ministry that is protected on both ends by police, though the checkpoints are easily driven past. The 8:30 a.m. explosion rattled much of Kabul and kicked up gray dust that shrouded the bodies of the dead and enveloped the survivors — a monochromatic coating broken only by the crimson blood of the wounded. The blast blew clothing off many victims.

President Karzai condemned the bombing and said it was carried out by militants trying to rupture the Afghan-India friendship. He told the Indian prime minister during a phone conversation that Afghanistan would do all it could do identify the attackers.

The Afghan Interior Ministry hinted that the attack was carried out with help from Pakistan’s intelligence service, saying the blast happened “in coordination and consultation with some of the active intelligence circles in the region.”

A spokesman for Pakistan’s Foreign Ministry declined to comment on the bombing. The Pakistani foreign minister said his country condemned the attack and all forms of terrorism.

The bombing showed that Afghanistan is also a theater for the struggle between longtime rivals India and Pakistan.

“These attacks seem designed to sabotage any improvement of relations between Pakistan and either of its two neighbors, India and Afghanistan, to assure that Pakistan has no alternative but to continue to support militant organizations as part of its foreign policy,” an Afghanistan expert at New York University, Barnett Rubin,said.

At Kabul’s hospitals, anguished parents railed against the Afghan government.

“Where is the security?” a father of four who knew that two of his children had been killed, Mirwais, cried. Before heading to another hospital to search for his other two children, he shouted obscenities at Karzai.

Moments later, a woman ran outside screaming, crying and hitting her face with both hands. Her son and daughter had been killed. “Oh my God!” the woman screamed. “They are both dead!”

Six police officers and three embassy guards were among the dead.

In New Delhi, India’s foreign minister said four Indians, including the military attache and a diplomat, were killed.

The blast also killed five Afghan security guards at the nearby Indonesian Embassy, where windows were shattered and doors and gates broken. Two diplomats were slightly wounded, Indonesia’s foreign ministry said.

In Washington, the White House offered condolences to the victims.

“Extremists continue to show their disregard for all human life and their willingness to kill fellow Muslims as well as others,” a White House national security spokesman, Gordon Johndroe, said. “The United States stands with the people of Afghanistan and India as we face this common enemy.”

Afghanistan has seen a sharp rise in violence from Taliban militants in recent months. Insurgents are packing bombs with more explosives than ever, one reason why more American and NATO troops were killed in June than any month since the 2001 invasion.

Still, no one claimed responsibility for the blast, and a Taliban spokesman, Zabiullah Mujahid, denied the militants were behind it. The Taliban tend to claim responsibility for attacks against international or Afghan troops and deny responsibility for bombs that primarily kill civilians.

“Whenever we do a suicide attack, we confirm it,” Mr. Mujahid said. “The Taliban did not do this one.”

The explosion was the deadliest in Afghanistan since a suicide bomber killed more than 100 people at a dog fighting competition in Kandahar in February.

The Indian embassy in the last several days had beefed up security by installing large, dirt-filled blast walls often used by military forces.

The Indian Ministry of External Affairs said the attack would not deter its country’s mission to fulfill “our commitments to the government and people of Afghanistan.”

Pakistan views with suspicion India’s involvement in Afghanistan, including the millions of dollars donated for reconstruction and the thousands of Indian engineers and laborers helping to build roads and other infrastructure.

Pakistanis are also wary of Indian consulates that have been established in the outlying cities of Kandahar, Jalalabad, Herat, and Mazar-i-Sharif. But Indian officials say they are there to support reconstruction. Militants have frequently attacked Indian offices and projects around Afghanistan.

A political analyst in Pakistan, Ikram Sehgal, said he doubts Pakistan’s intelligence service was behind the attack. He instead blamed Pashtuns — the largest of Afghan ethnic groups that also forms the core of the Taliban insurgency.

“The Indians were asking for it,” Mr. Sehgal said. “They have set up so many consulates along the border….It was question of time. The (Pashtuns) see them as enemies, actually. They had to react to the Indians setting up consulates there.”

Pakistan and India have fought three wars since their independence from Britain in 1947. Kashmir is divided between Pakistan and India, and India says Kashmiri militant groups — which are seeking independence or to merge Kashmir with Pakistan — get military and financial support from Islamabad. Pakistan says it only supports the rebels’ cause morally.

Afghanistan’s allegations that Pakistan was involved in today’s attack will probably only sour already troubled relations.

Late last month, a spokesman for Afghanistan’s intelligence agency accused Pakistan’s premier spy agency of organizing an April assassination attempt on Mr. Karzai.

Afghan leaders also allege that Pakistan secretly supported a June 13 insurgent attack on a prison in the southern city of Kandahar that freed 400 Taliban fighters.

And Mr. Karzai last month threatened to send Afghan troops after Taliban leaders in Pakistan, saying he had had enough of cross-border militants attacks.

The Afghanistan foreign minister, Rangeen Dadfar Spanta, visited the embassy shortly after the attack and said the blast would not harm relations between the two countries.

The United Nations and NATO’s International Security Assistance Force both condemned the attack.

The embassy attack was the sixth suicide bombing in Kabul this year. Insurgent violence has killed more than 2,200 people — mostly militants — in Afghanistan in 2008, according to an Associated Press count of official figures.