Fears that Ukraine could split in two mounted yesterday as protesters seized the Kiev office of President Viktor Yanukovych and opposition lawmakers pressed on with forming a new cabinet.
Regional lawmakers in the pro-Russian east, meanwhile, questioned the authority of the national parliament and said they were taking control of their territories.
The embattled president, who left Kiev for his stronghold in eastern Ukraine, said he was not resigning and slammed the crisis as a coup, saying it resembled the rise of the Nazis in the 1930s.
"Everything that is happening today is ... vandalism and bandits and a coup d'état," Yanukovych said in a televised statement. He said he would not sign any of the measures passed by parliament, which include trimming his powers and releasing his jailed arch-rival, ex-prime minister Yuliya Tymoshenko.
This came as the army ruled out taking any involvement in the crisis that is rocking the country, just hours after police pledged to support the people.
In Moscow, Russian Foreign Minister Sergey Lavrov said the Ukrainian opposition had failed to deliver and urged his German, French and Polish counterparts, who helped broker Friday's agreement, to exert their influence to improve the situation.
At the president's headquarters, Ostap Kryvdyk, who described himself as a protest commander, said some protesters had entered the offices but there was no looting. "We will guard the building until the next president comes," he said.
The grounds of Yanukovych's residence outside Kiev were also being guarded by "self-defence" militia of protesters.
The speaker of parliament, a Yanukovych loyalist, resigned and parliament elected Tymoshenko ally Oleksander Turchynov as his replacement.
It took hard lobbying to persuade the opposition to accept the deal, and crowds in the streets made clear they were not satisfied with an arrangement that would leave Yanukovych in power. Protesters remained encamped in Independence Square, known as the Maidan, all night. They held aloft coffins of slain comrades and denounced opposition leaders for shaking Yanukovych's hand.