The Ukrainian opposition vowed to press on with protests despite President Viktor Yanukovych's offer of top posts in a power-sharing deal. Protesters took control of another strategic building in the capital, Kiev.
Two months after the protests began over his decision to back out of an EU pact, Yanukovych on Saturday offered to share leadership with Arseniy Yatsenyuk as prime minister and Vitali Klitschko as deputy prime minister in a bid to end the crisis.
Opposition leaders said that they would continue negotiations until other demands were met, and that they aimed to take power in a snap presidential poll.
Protesters meanwhile scored another victory after taking control of a building in central Kiev yesterday by ousting some 200 police officers that used it as base. In a siege overnight of the Stalin-era exhibition hall called Ukrainian House near the protest zone, protesters threw firebombs. Police responded with stun grenades.
Tensions eased after troops were allowed to exit by a side entrance to cries of "Shame!" from protesters. The interior ministry later said the minister gave the order to "withdraw the reserve unit" and accused protesters of attempting to take troops hostage.
"The goal of the protesters was taking the policemen captive and exchanging them for arrested or detained activists," the ministry said.
Klitschko, head of the UDAR party, said the protesters did not plan to use the building but would guard its entrances so police did not return.
Officials say three people have been killed in the escalating protests in Kiev over the past week, raising fears of a wider civil conflict; protests have spread to outlying regions of Ukraine in the former Soviet republic's worst crisis since independence in 1991.
The Ukrainian presidency said after Saturday's talks with opposition leaders that Yanukovych was willing to shuffle his government and consider constitutional changes that would reduce presidential power and return to a system where the prime minister has more authority. The president also agreed to initiate an amnesty bill for arrested protesters and to reconsider anti-protest laws passed by parliament this month.
Speaking to tens of thousands packed into Independence Square late on Saturday, the main opposition leaders were careful to neither accept nor reject Yanukovych's proposal to share leadership.
"We are not refusing the offer but we are not accepting it either," Yatsenyuk said. He later wrote on Facebook that the opposition should be the one dictating terms. Klitschko told protesters "talks will continue" and the opposition would press for a presidential election due in 2015 to be held this year.