HELSINKI (AP) — The European Union’s border agency said Thursday that it will send dozens of officers and equipment as reinforcements to Finland to help police its borders amid suspicion that Russia is behind an influx of migrants arriving to the country.

Frontex said that it expects a “significant reinforcement” made up of 50 border guard officers and other staff, along with patrol cars and additional equipment, to be put in place as soon as next week.

Around 600 migrants without proper visas and documentation have arrived in Finland so far this month compared to a few dozen in September and October. They include people from Afghanistan, Iraq, Syria, Yemen, Kenya, Morocco and Somalia.

On Wednesday, Finnish border guards and soldiers began erecting barriers, including concrete obstacles topped with barbed-wire at some crossing points on the Nordic country’s lengthy border with Russia.

The government decided to close four busy Russia border crossings in southeastern Finland last week over suspicions of foul play by Russian border officials. It plans to only leave one Arctic crossing point open for migrants seeking asylum. The Kremlin denies the allegations.

Frontex Executive Director Hans Leijtens said that sending border reinforcements is “a demonstration of the European Union’s unified stand against hybrid challenges affecting one of its members.”

Finland has nine crossing points on the border with Russia, which runs 1,340 kilometers (830 miles) and serves as the EU’s easternmost frontier as well as a significant part of NATO’s northeastern flank. Finnish authorities believe that Russia has become more hostile toward Finland since the country joined NATO in April.

EU Home Affairs Commissioner Ylva Johansson said this week that the challenges on Finland’s border gave her a feeling of “deja vu,” two years after Belarus began driving migrants into Latvia, Lithuania and Poland in what European officials said was an attempt to destabilize the 27-nation bloc.

“The Finnish border is the EU’s border,” Johansson told EU lawmakers in a message of support to Helsinki. “The European Union is behind you. You can count on our full support to protect the EU border and uphold fundamental rights.”

The governor of Russia’s northern Murmansk region recently said the region would be put on “high alert” after Finland announced that it would close all border crossings between the two countries apart from one.

Gov. Andrei Chibis said that he expected the number of foreigners trying to cross to Finland from the last remaining open border post in the Murmansk region to “exponentially” increase.

Chibis said there were 400 people waiting to enter Finland at the more southerly Finnish Salla border post on Wednesday, of which only 50 were allowed to cross.

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Lorne Cook reported from Brussels.

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