Unrest in northern Kyrgyzstan has spread to the capital city Wednesday as some 10,000 protesters are marching toward central Bishkek after breaking a police picket line in a suburb of the city, witnesses said.

Earlier media reports quoted the Central Asian country's prosecutors as saying that some opposition leaders had been arrested and accused of "serious crimes".

In an interview with Xinhua earlier Wednesday, Kyrgyz Prime Minister Daniyar Usenov accused the opposition for "deliberately masterminding" Tuesday's unrest in the northern Kyrgyz town of Talas.

Kyrgyz Interior Minister Moldomusa Kongantiyev said Tuesday evening that the unrest in Talas has been put under control.

At a news briefing in the presidential palace, Kongantiyev said police have arrested Bolot Sherniyazov, a key opposition party leader, and will send him to the capital Bishkek for further questioning.

He also said that the governor of Talas who was held as hostage has been rescued and he is in good health.

According to the interior minister, most of the people involved in anti-government activities were young people who were taken in by the opposition parties.

Kongantiyev stressed that the upcoming so-called "people's conference" rallies to be staged by the opposition parties have not been approved by the government and are thus illegal.

If the opposition parties insist on holding such rallies in the next few days to undermine social stability, the government will take tough measures against them, he added.

Kongantiyev warned that the opposition leaders who organized Tuesday's riots and directed the assault on the Talas government building will be investigated for criminal responsibilities and those who committed serious offences will be prosecuted.

Local media reported that on Tuesday afternoon, about 1,000 protestors stormed the regional government building, who were later dispersed the police.

Press here said the unrest was triggered by the police's arrest of opposition leader Sherniyazo, which angered many opposition supporters.

A source told Xinhua on the phone that up to now, there were still about 5,000 people trying to storm local police stations in the city of Talas and the policemen were busy calming down the situation.

He said he saw the first floor of the regional government building was seriously damaged by burning and some people were supplying rioters with pebbles to help them confront the riot police. He also spotted many wounded policemen on the streets.

The riot police were trying to use tear gas, firebombs and rubber bullets to disperse the rioters, but met with strong resistance.