A dramatic surge in the number of migrants from Africa and the Middle East arriving on the EU’s eastern frontier are part of a “blatant hybrid attack” orchestrated by Moscow, Estonia’s foreign minister said, warning that crossings from Russia could be banned altogether.

In a statement Wednesday, Margus Tsahkna said the Baltic nation is “prepared to close its border with Russia” if the situation continues. The growing crisis, he added, “is yet more proof that Russia is not fighting only in Ukraine; instead it poses a threat to other countries.”

At the same time, Estonian Interior Minister Lauri Läänemets said the government was planning to deal with a potential rise in the number of crossings after Finland closed all of its checkpoints with Russia on Tuesday, accusing the Kremlin of attempting to stoke a migrant crisis. Helsinki argues Moscow’s “influence activity” is intended as retribution for the Nordic country’s decision to join NATO in the wake of the full-scale war in Ukraine.