Poland, Baltics will shut Belarus border if 'critical incident' occurs -minister

WARSAW (Reuters) -Poland and the Baltic states will close their borders with Belarus entirely if a "critical incident" involving Wagner mercenaries takes place, the Polish interior minister said on Monday, amid rising tensions on NATO's eastern flank.

EU and NATO members Latvia, Lithuania and Poland, which share a border with Belarus, have been increasingly concerned about border security since hundreds of Russian battle-hardened Wagner mercenaries arrived in Belarus at the invitation of President Alexander Lukashenko.

The countries have also seen an increase in the number of mainly Middle Eastern and African migrants trying to cross the border in recent months and accuse Belarus of facilitating them, a claim Minsk rejects.

"We demand from the authorities in Minsk that the Wagner Group immediately leave the territory of Belarus and that illegal migrants immediately leave the border area and are sent back to their home countries," Mariusz Kaminski told a joint press conference with his Lithuanian, Latvian and Estonian counterparts.

"If there is a critical incident, regardless of whether it is at the Polish or Lithuanian border, we will retaliate immediately. All border crossings that have been opened so far will be closed," he said.

The Belarusian foreign ministry did not immediately respond to an emailed request for comment.

With Wagner boss Yevgeny Prigozhin believed killed in a plane crash last week, the fate of the web of military and commercial operations he and Wagner created for Russia across Europe, the Middle East and Africa hangs in the balance.

Lithuanian Interior Minister Agne Bilotaite told media that there were two criteria that could lead to a border closure.

"First of all, an armed incident at the border of one of the countries. The incident would need to pose serious threat to national security," she said "The other criterion is a mass breakthrough of migrants through the border of one of the states."

Bilotaite said Lithuania's interior ministry will propose to the government closing two out of the country's four remaining border crossing points with Belarus, a move she said would curb contraband and would concentrate more officers at the remaining border crossings.

Poland has closed all but one border crossing point with Belarus this year following the imprisonment of a journalist of Polish origin and expulsions of Polish diplomats.

(Reporting by Alan Charlish, Pawel Florkiewicz, Marek Strzelecki in Warsaw, Andrius Sytas in Vilnius; Editing by Conor Humphries and Nick Macfie)