The protesters overran the regional police and security stations on Monday and forced about 100 troops to flee in the latest of a wave of protests to demand President Askar Akayev's resignation.
Aljazeera's reporter in Moscow, Akram Khuzam, said the protesters had stormed the Intelligence and Interior Ministry buildings.
The Itar-Tass news agency quoted unnamed police officials as saying police around the buildings did not offer any resistance to the crowd.
In the capital Bishkek, sources told Aljazeera the central government had totally lost control of the situation in the southern Kyrgyzstan cities of Jalalabad and Osh.
The sources said power was now in the hands of what were described as 'organised criminal groups' which had already seized control of the booming drugs trade in these areas.
The unrest began early this month over alleged election breaches in the 27 February parliamentary polls, and intensified after the subsequent runoffs that the opposition and international observers said were seriously flawed.
Monitors from the Organisation for Security and Cooperation in Europe (OSCE) criticised Kyrgyzstan's two-round parliamentary poll, pointing to vote buying, disqualification of opposition figures and media manipulation.
Demonstrators have taken to
Demonstrations were reported to have turned violent on Sunday, with four people reported dead among the protesters and four among law enforcement officers.
Khuzam said there was no reaction from the authority and excluded any immediate reaction to the opposition protests.
On Monday, several thousand people were gathering in the town's central square, chanting "Akayev Out". Some were carrying sticks.
Opposition demands talks
The opposition urged the government to agree to talks to defuse the stand-off in the impoverished south.
In Bishkek, a coalition of opposition parties said it had written to Akayev, urging him to agree to talks.
"In the current dramatic situation, we demand that we get around the negotiating table. We await a reply," said Ishengul Boldzhurova, one of the leaders of the coalition.
Akayev has warned that any attempt to copy Ukraine's Orange Revolution could drag the mostly Muslim country of nearly five million into civil war.
President Askar Akayev has
refused to step down
He has rejected calls to step down, but his officials have said they will not use force against the protesters.
Khuzam said if the authorities decided to react, it would be forced to go for a military option, and that would draw local and international condemnation.
The opposition has launched similar protests in at least eight other cities and towns over the past several days.
Central Asian Kyrgyzstan has become the latest former Soviet republic - after Ukraine and Georgia - to be rocked by anti-government protests in the wake of elections judged as flawed by international observers.
Akayev has been the president of Kyrgyzstan, a poor, landlocked country with 50% of its population below the poveryt line, since 1990.