The emboldened opposition has called for massive demonstrations on Sunday to pressure Belarus' authoritarian leader into resigning after more than two weeks of historic protests against his disputed re-election.

Europe's longest serving leader, Alexander Lukashenko, dispatched his notorious riot police to disperse spontaneous rallies that erupted after he claimed a sixth presidential term in August 9 elections that Western leaders have said were rigged.

Solidarity rallies were also scheduled in neighbouring Lithuania, where demonstrators planned to form a human chain from Vilnius to the border with Belarus, 31 years after residents of the Baltic states joined hands and linked their capital cities in a mass protest against Soviet rule.  

The EU has rejected the results of the presidential elections and this week promised to sanction Belarusians responsible for ballot fraud and a police crackdown that saw nearly 7,000 arrested and sparked gruesome allegations of torture and abuse in police custody.

Lukashenko has brushed aside the unprecedented calls to stand down, dismissed the possibility of holding a new vote and instructed his security services to quell unrest and secure the borders.

His judiciary opened a criminal investigation into the opposition's Coordination Council that seeks new elections and the peaceful transition of power, after he said opponents wanted to "seize power".

- NATO 'stirrings' -

The former collective farm boss ordered his army into full combat readiness during an army inspection on Saturday near the border with the EU and warned about NATO troop "stirrings" in Europe.

"The Fatherland is now in danger. We cannot joke," Lukashenko said. Lithuania's president Gitanas Nauseda in turn said Lukashenko was trying to "divert attention" from unrest at home and NATO dismissed the claims as baseless.

The unlikely leader of Belarus's opposition, 37-year-old Svetlana Tikhanovskaya, fled to Vilnius fearing reprisals for claiming victory in the elections and mounting the greatest challenge to Lukashenko over his 26-year rule.

In an interview with AFP ahead of the demonstrations, she urged protesters to continue to exert pressure on the authorities saying it was "important to continue to be united in the struggle for the rights".

- 'Not afraid' -

The authorities have to understand "we are not a protest movement ... we are a majority and we will not step away. We are not afraid of them anymore," Tikhanovskaya told AFP.

Opponents of Europe's longest serving leader have organised strikes and the largest protests in the ex-Soviet country's recent history rejecting his re-election and demanding that he stand down, with more than 100,000 people turning out in Minsk alone last weekend.

Yet fewer workers at state-run factories -- usually a bastion of support for Lukashenko -- have continued to strike, with activists citing pressure from the authorities.

The 65-year-old president of Belarus has threatened to shutter production lines where workers have put down their tools beginning on Monday.

Staff at state-run media outlets have also staged walkouts and Lukashenko admitted this week that journalists from Russia had been flown in to replace them.

His powerful ally, Russia, has warned European leaders against interfering in Belarus and the Kremlin has said it would intervene in the post-election unrest if necessary.

Russia and Belarus are members of a military alliance of former Soviet countries and Lukashenko said on Saturday he had  warned Russia about the situation in its ex-Soviet neighbour. 

Lithuania's foreign ministry announced Saturday that US Deputy Secretary of State Stephen Biegun will visit Lithuania and Russia next week for talks on the election fallout.

Lukashenko' military inspection this weekend inspection came ahead of large-scale military exercises planned in the Grodno region on the border with the European Union between August 28 and 31.