MOSCOW, Russia - Belarus said Tuesday it is further restricting citizens from leaving the country, including those with foreign residency permits, in a move the opposition denounced as "an absolute violation of the law".

The development comes as dozens of Belarusians, some of them illegally, have been fleeing their country in recent months amid a bloody crackdown in the wake of the disputed re-election of President Alexander Lukashenko last August.

The Belarusian border guards service said it has "received recently many requests to leave Belarus on the basis of a (foreign) residence permit," according to a statement published on the Telegram messaging app.

However, it said only citizens with papers granting them a "permanent stay in a foreign state" had the right to leave Belarus.

It added that "permission for a temporary stay... does not constitute a reason for travelling abroad."

Under Lukashenko, who has ruled the country since 1994, Belarus imposed restrictions on foreign travel in December 2020, framing the decision in the context of fighting the coronavirus pandemic.

Leaving the country by land routes is in any case only possible once every six months.

"The Lukashenko regime has severely limited the right of Belarusians to travel, asserting that certain reasons are not sufficient to leave Belarus," said Valery Kovalevsky, an advisor to opposition leader Svetlana Tikhanovskaya, who lives in exile in Lithuania.

"However, the constitution foresees no condition," he added, denouncing what he called "an absolute violation of the law."

Air travel remains open, but the destinations have been limited since the European Union banned Belarusian planes from its air space after Minsk last month scrambled a fighter jet to divert a Ryanair flight and arrested a dissident journalist onboard.

EU country Lithuania, which neighbours Belarus, has offered support to fleeing Belarusians by granting them six-month visas.