Ukraine protesters leave city hall in Kiev. Photo: BBC NEWS

"City hall is almost completely evacuated", opposition spokesman Ruslan Andriyko told AFP.

The government had promised to drop all charges against demonstrators if they vacate government buildings and lift roadblocks by Monday.

City hall has been occupied by protesters for more than two months.

The protests started in November when President Viktor Yanukovych abandoned plans to sign a far-ranging association agreement with the EU.

Instead, he advocated closer trade relations with Russia, which dominated Ukraine for centuries until the fall of the Soviet Union in 1991.

Prisoners released

People began walking out of the building on Sunday morning.

The Swiss ambassador in Kiev entered the building soon afterwards in order to help transfer the building to the control of the authorities.

Switzerland currently holds the rotating presidency of the Organisation for Security and Cooperation in Europe.

On Friday authorities released the last of 243 prisoners who were arrested during the unrest.

Mr Yanukovich passed an amnesty law earlier this month and agreed to negotiate with the opposition after at least four people were killed in protests.

This weekend, some opposition members continued to call for his departure, and another demonstration is due to place in Kiev's central Independence Square.

"The only subject of negotiation with Yanukovych is the conditions of his departure," jailed opposition leader Yulia Tymoshenko said on Saturday.

She went to accuse the Ukrainian president of being under the control of Russia's Vladimir Putin, his major international backer.