BISHKEK, Kyrgyzstan — The president of Kyrgyzstan declared from hiding Thursday that he would not surrender to a violent uprising that put the opposition in control of much of the country, home to a U.S. air base key to the war in nearby Afghanistan.

Just after he spoke, automatic weapons fire broke out in the capital miles from the Manas facility, where flights were at least temporarily halted and troops were confined to the base.

It was not clear if Kyrgyz forces controlled by the opposition in Bishkek were battling loyalists of President Kurmanbek Bakiyev, or simply firing to deter looters after nightfall. There appeared to be little evidence of armed men loyal to Bakiyev in the capital before dusk.

The opposition has seized vital official buildings in Bishkek and elsewhere and was giving orders to at least some security forces, declaring it controlled four of the nation’s seven provinces. Opposition leader Roza Otunbayeva said parliament had been dissolved and she would head an interim government that would rule for six months until elections were held. She urged Bakiyev to resign.

Bakiyev, who has fled the northern capital for his stronghold in the south, told a Russian radio station that “I don’t admit defeat in any way.” But he also said he recognized that “even though I am president, I don’t have any real levers of power.”

Although the opposition has previously voiced objections to Manas, Otunbayeva said there were no plans yet to review the lease that runs out in July and that her government would meet U.S. diplomats for talks.

“Give us time, it will take time for us to understand and fix the situation,” Otunbayeva said.

U.S. military officials said about 1,100 troops are at the Manas air base, including contingents from Spain and France. They are supporting NATO operations in Afghanistan.

Choas erupted Wednesday in this mountainous former Soviet republic when protesters furious over corruption and soaring utility bills stormed government buildings in Bishkek. Riot police fired straight into crowds. The Health Ministry said at least 74 people were killed and 400 people were hospitalized.