Lithuania, Latvia and Estonia imposed as the first EU countries imposed sanctions on Belorussian dictator Alexander Lukashenko and 29 other Belarusian officials on Monday, signalling impatience with the West's cautious approach.

The three Baltic states have led calls for the West to take firmer measures against Mr Lukashenko, who is accused by opponents and the West of rigging an election to prolong his 26-year rule. The sanctions, announced simultaneously by the three Baltic countries, target officials that they accuse of vote rigging and playing a role in violence against protesters since the August 9 election. Including Lukashenko himself atop the list was a prod at other European countries, which have so far been reluctant to back measures against him personally.

The three small Baltic states are all members of the EU and NATO, and Lithuania and Latvia border Belarus.

Lithuania has been hosting Belarusian opposition presidential candidate Sviatlana Tsikhanouskaya, who fled there after the election her supporters say she won.

Ms Tsikhanouskaya will speak to the UN Security Council on Friday at Estonia's invitation, her spokesman said.

Three weeks into a mass demonstration movement that has peaked on the weekends, tens of thousands of protesters again took to the streets in central Minsk on Sunday, seeking to keep up pressure on Mr Lukashenko to resign. At least 140 people were detained.