Polish Prime Minister Donald Tusk announced this morning that authorities have identified the two suspects behind Sunday’s sabotage of several critical railway sections in Poland — including an attempted detonation of a rail segment using C4 — as Ukrainian nationals long linked to Russian intelligence.

One suspect had previously been convicted of sabotage in Lviv, while the other is from the Donbas region in eastern Ukraine. Both had been living in Belarus and entered Poland earlier this fall, fleeing back to Belarus after carrying out the attacks.