Opposition activists have seized government buildings in Kyrgyzstan's second largest city, Osh, as protests against disputed elections continue.
Security forces were forced to flee the building as protests mounted
About 1,000 protesters took control of the regional government building and forced police to flee, reports said.
The move followed the opposition's effective seizure of parts of the nearby town of Jalal-Abad on Sunday.
The opposition wants President Askar Akayev to resign, and says recent elections for parliament were unfair.
Protests have been gathering momentum in the south of Kyrgyzstan since run-off elections on 13 March, when opposition parties won only a handful of seats in parliament.
The protests have drawn comparisons with other popular upheavals in the former Soviet states of Georgia and Ukraine, although Mr Akayev has warned that such an development would risk civil war in Kyrgyzstan.
In Osh, protesters first stormed the regional government building on Friday, but were forced out.
On Monday, many of the returning protesters carried shields dropped by riot police who turned and fled as the crowd rushed the building.
The BBC's Central Asia correspondent, Monica Whitlock, says most security forces seem to have escaped unhurt, but rioters caught two, beat them up, and paraded them on horseback around the square.
The demonstrations came after about 10,000 people besieged and then burnt down the police station in Jalal-Abad on Sunday and blocked the airport's runway to prevent the government flying in re-enforcements.
Police said four officers were killed in the protests.
Call for talks
Kyrgyzstan's Prime Minister Nikolai Tanayev said the government was ready to talk to the protesters, and promised that force would not be used.
"Not the president, not me, and not the interior minister will allow weapons to be used against our own people," he said .
But an opposition leader said talks would only be worthwhile if President Akayev himself took part.
"All other lower level negotiations will be just a waste of time," Kurmanbek Bakiyev of the People's Movement of Kyrgyzstan told the Associated Press news agency.
Our correspondent says it is not at all clear who from the opposition could lead any talks.
The protests are local, there is no unifying opposition figure or party, and Kyrgyzstan's rough mountainous terrain and poor infrastructure make communications difficult, our correspondent says.
The latest protests are also taking place in a highly sensitive region, close to the border with Uzbekistan.
A sizeable proportion of the region's population is ethnically Uzbek. They, along with some ethnic Kyrgyz in the south, tend to view ethnic Kyrgyz leaders in the capital Bishkek with suspicion.
Police shot dead several demonstrators at a similar protest three years ago, and in 1990 hundreds of people were killed in inter-ethnic violence in the area.
In Washington, State Department James Ereli on Sunday said US officials have been in touch with both sides, to urge them to resolve their differences through dialogue.