BANGKOK, Thailand — Armed protesters attempted to overthrow Thailand’s elected government yesterday by storming the prime minister’s residence and the state television station in Bangkok, the capital.

Demonstrations by the same nationalist group in 2006 were used by the army as a pretext to oust Thaksin Shinawatra as prime minister and “restore order,” but this time the military said it would not intervene.

The People’s Alliance for Democracy wants to replace elected politicians with legislators appointed by the bureaucracy and the army.

Eighty-five people were arrested after they attacked the state broadcaster’s office armed with a pistol, catapults, and golf clubs. They finally occupied the building and twice succeeded in taking the channel off the air. Later, protesters scaled the fence of the gothic mansion owned by the current prime minister, Samak Sundaravej.

A protest leader, Sondhi Limthongkul, described the events as the “final showdown” that will topple the government of Mr. Sundaravej, an ally of Mr. Thaksin, who came to office six months ago.

Mr. Thaksin, who bought Manchester City football club last year, fled Thailand this month and is seeking asylum in Britain. In Thailand he faces corruption allegations relating to his time in office and could be jailed if he returns.

Thousands of PAD supporters were camped inside the compound of Mr. Samak’s official residence last night. “We are now in Government House and won’t move until the government resigns,” Mr. Sondhi told his cheering supporters.

Mr. Samak told a hastily arranged meeting of foreign journalists: “They want bloodshed in the country, they want the military to come out and stage a coup again. I will not resign. I will stay to protect this country.”

The protesters invaded the television station before dawn and went on to block roads and besiege government ministries. By the afternoon the broadcaster’s office resembled a hippy sit-in, as demonstrators lounged and sang protest songs.

There were similar scenes at Government House. Dressed in yellow, to symbolise their loyalty to Thailand’s revered monarchy, thousands thronged the gardens. But despite the easy-going atmosphere, and the protesters’ stated support for democracy, their agenda is far from liberal. Besides shifting power from parliament to the army, they want to disenfranchise the rural poor who have consistently voted for Mr. Thaksin and Mr. Samak, on the grounds that they are too simple to choose their leaders wisely.

The Foreign Office warned British holidaymakers in Thailand to be cautious and avoid any demonstrations or large gatherings.