Belarus on Thursday said it will temporarily close its land border in late December to curb the spread of the coronavirus, a move that the opposition viewed as a further clampdown on dissent.

According to a government decree, Belarus nationals and foreigners who hold temporary or permanent residency will not be able to leave the country via land border checkpoints starting December 20.

The decree did not state how long the measure will last.

For over four months, the ex-Soviet republic has been gripped by historic anti-government protests that erupted following an August presidential election in which incumbent Alexander Lukashenko secured a sixth term in office.

Lukashenko's opponents believe the polls were rigged and that political novice Svetlana Tikhanovskaya, who ran against Lukashenko in place of her jailed husband, was the true winner of the election. 

Several western leaders have refused to recognise the election results and backed Tikhanovskaya, who fled to neighbouring Lithuania shortly after the vote. 

The European Union imposed sanctions on Lukashenko and his allies citing election rigging and a violent police crackdown on protesters. 

In response to the border closures, Tikhanovskaya on Thursday said that the "regime is doing everything to turn our country into a modern Gulag", referring to the Soviet-era labour camps established under Joseph Stalin. 

Lukashenko "fears publicity and justice and hopes that closed borders will help hide all his crimes," Tikhanovskaya wrote on her Telegram channel.

Several Belarusian opposition figures have fled across the border to EU members Poland, Lithuania and Latvia in the wake of a brutal crackdown on the protests. 

The new border restrictions will apply to all border checkpoints on the ground, including those at railways and river ports. Entry via Minsk National Airport -- the country's main international airport -- will remain open. 

Exceptions will be made for diplomats, Belarus citizens holding residency abroad and those travelling for study or in the case of a serious illness or death of a close relative. 

At the start of the pandemic this spring, Lukashenko repeatedly dismissed virus concerns and did not impose a nationwide lockdown. 

The 66-year-old strongman leader is rarely seen wearing a mask or taking precautionary measures even though he has said he had contracted an asymptomatic case of the coronavirus this summer.