Thousands of protesters are rallying for a second day in the Kyrgyz capital, Bishkek, as the government accused the opposition of planning a coup.
Protesters say they will stay until the president resigns
Kyrgyz Prime Minister Felix Kulov told parliament that security services had recorded opposition leaders discussing seizing state buildings.
But a BBC correspondent in Bishkek said that so far the protests were peaceful.
Opposition supporters, who began their protest on Wednesday, are demanding the president's resignation.
They accuse President Kurmanbek Bakiyev of failing to introduce the democratic reforms he promised when he came to power in 2005, and have pledged to continue until their demands are met.
'There are intentions'
Many protesters remained camped overnight in Bishkek's main square, says the BBC's Natalia Antelava.
The government said the opposition planned to seize state buildings
Several hundred of them marched on the state television building to demand airtime for their leaders, while thousands more gathered in the square to hear a series of speeches.
They insist their protest will continue to be well organised and peaceful, our correspondent says.
But in parliament, the prime minister said he had evidence a coup was being planned by opposition leaders.
"They talked about seizing the city hall, the Committee for State Security, state television and some buildings in the provinces," Mr Kulov said, according to the Associated Press news agency.
Mr Bakiyev appeared to play down the threat.
"There is no threat here. There are no forces to carry out a coup. But there are intentions," Reuters news agency quoted him as saying.
TULIP REVOLUTION WILTS
March 2005 - Former President Akayev ousted in popular protest
July - Kurmanbek Bakiyev elected President
April 2006 - Thousands protest for end to corruption and crime
November - Opposition calls for constitutional reform and curbing of presidential powers
The opposition had rejected the allegations, AP reported. "There was no coup attempt," leader Omurbek Tekebayev was quoted as saying.
Hundreds of police have been deployed around the presidential headquarters, reports said.
The rally comes after weeks of political crisis and several rounds of failed negotiations over constitutional reform.
Opposition leaders accuse the president of breaking a pledge he made earlier in the week to hand more of his powers to the parliament and cabinet.
Mr Bakiyev won a landslide victory after President Askar Akayev was ousted in a popular protest - called the Tulip Revolution - in March 2005.