Ukrainian President Viktor Yanukovych offered Saturday night to make two of his adversaries prime minister and deputy prime minister, pledged to support amending harsh new laws against protest and proposed changing the constitution to give more power to the parliament.

Not good enough, answered opposition leaders, buoyed by the sudden eruption of protests all across the country against Yanukovych’s government and the ruling Party of Regions.

Ukraine’s capital, Kiev, witnessed a dramatic gathering of momentum Saturday behind the months-long effort of the protest movement to reduce or eliminate Yanukovych’s power. The opposition leaders, reaching for more than what has been offered, have shown that they are extraordinarily wary of any of the president’s pronouncements — yet they run a risk if they appear to be too intransigent. The president still wields considerable power and enjoys popular support in the eastern regions of his country.

“We are ready to take responsibility,” said Arseniy Yatsenyuk, the head of the opposition Fatherland party and the man Yanukovych had offered to make prime minister.

Yatsenyuk declined the deal for now. “We’re finishing what we started. The people decide our leaders — not you,” he said. But he made it clear there is room for negotiation.

In a three-hour meeting with his opponents Saturday evening, Yanukovych offered the deputy prime minister’s job to the boxer Vitali Klitschko, the head of the UDAR party who has emerged as perhaps the most formidable opposition leader. But Klitschko announced afterward to the crowd on the Maidan, or Independence Square, that there was no deal. The two sides need to keep talking, he said.

Yanukovych’s stated willingness to amend the laws passed Jan. 16 restricting freedom of speech and assembly wasn’t sufficient, Klitschko said, and he called for their repeal instead.

Yanukovych did not offer a position to the third principal opposition leader, the nationalist Oleh Tiahnybok of the Svoboda party.

Tiahnybok credited the emergence of the “ultras,” fanatical and usually nationalistic supporters of soccer teams, on the side of the opposition this past week for the sudden change in tone in Yanukovych’s position.

“We put the squeeze on him,” he said.

In cities throughout western Ukraine, and in some places elsewhere, protesters continued their occupations and their attempts to seize government buildings. In Lviv, a stronghold of anti-Yanukovych sentiment, the city council recognized the “People’s Rada,” a council created by the opposition, as the governing body of Ukraine.

The Associated Press reported that more violence broke out in Kiev late Saturday as a crowd attacked a government conference hall where police were stationed. According to the AP, protesters were throwing firebombs at the building and police were responding with tear-gas.

The protests began Nov. 21 when Yanukovych reversed course and nixed a trade deal with the European Union, turning instead to Russia for financial aid. The move jolted Ukrainians who were longing to move their country toward Europe and who loathed the idea of giving Moscow more power over their country.

The protesters soon widened their demands. They wanted Yanukovych to fire the interior minister and Prime Minister Mykola Azarov. Then they began calling for early presidential elections and campaigned strongly against corruption and police brutality, both of which are endemic in Ukraine.

For two months, the protesters had little to show for their efforts besides the draconian laws against their gathering that parliament rushed through Jan. 16.

This past week, the protest turned fatal. With at least three people shot to death and a third beaten and left to freeze, the stakes got much higher.

Hundreds of police troops were wounded. A police officer on his way home Friday night was accosted and shot to death by unknown assailants.

Yanukovych accepted the resignations of two top aides Saturday. They were his spokeswoman, Daria Chepak, and Andriy Yermolayev, director of the National Institute of Strategic Studies, Ukraine’s state think tank.