Polish Prime Minister Mateusz Morawiecki said Saturday that his government had received information that the Wagner mercenaries were not far from Grodno, a city in western Belarus close to the land, which is also known as the Suwalki gap or corridor.
Thousands of Wagner troops are reportedly in Belarus following a failed military uprising in Russia.
Morawiecki repeated allegations that Belarus, a key ally to Russia, has been sending migrants westward in an attempt to overwhelm Polish border forces.
The troop movements, Morawiecki said, appeared to be another element in this campaign to destabilize the border.
“They will probably be disguised as Belarusian border guards and will help illegal immigrants to enter Polish territory, destabilize Poland, but they will also probably try to infiltrate Poland pretending to be illegal immigrants and this creates additional risks,” he said.
So far this year, there have been about 16,000 attempts by migrants to cross the border illegally, “pushed to Poland” by Belarusian President Alexander Lukashenko and Russian President Vladimir Putin, Morawiecki said.
What exactly Wagner troops are doing in Grodno is unclear, as Wagner has not commented on the reports. But deploying Russian-allied forces near the Suwalki corridor would represent an escalation that could rattle NATO and EU members.
Though just 60 miles long, the corridor is strategically important to NATO, the EU, Russia and Belarus. The border region connects the Russian exclave of Kaliningrad to Belarus and it is the only overland link between the Baltic states and the rest of the EU.
Analysts feared in the early days of Russia’s invasion of Ukraine that the Kremlin would target the Suwalki corridor in an attempt to protect Kaliningrad, Russia’s westernmost territory and the only part of the country surrounded by EU states.
It is not clear exacttly how many Wagner troops are in Belarus. They were invited to the country as part of a deal negotiated by the Belarus president to end the mercenary group’s armed insurrection against the Kremlin last month.
Lukashenko then asked Wagner to help train his country’s military. The two plan to hold joint military exercises near the border with Poland, a move likely to further raise tensions.
At a summit Lukashenko joked with Russia’s President Putin that Wagner fighters had begun to stress him as they wanted to go west on “an excursion.”
Poland has said its borders are safe but has moved troops east due to possible threats posed from Wagner.
CNN’s Tim Lister and Rob Picheta contributed to this report