A railway line connecting Warsaw to southeastern Poland was damaged by a weekend explosion, which Prime Minister Donald Tusk on Monday described as an act of sabotage.

Tusk, who visited the site near the village of Mika, said the route is “crucially important for delivering aid to Ukraine” and confirmed that the explosion destroyed part of the track.

Officials reported that a train driver noticed irregularities on the line between Warsaw and Lublin around 7:40 a.m. Sunday. Further inspection revealed damage, but no injuries occurred among the two passengers and several staff members on board.

Defense Minister Władysław Kosiniak-Kamysz said the army will inspect 120 kilometers of the Warsaw-Lublin-Hrubieszów line, a key rail and road link to Ukraine. Interior Minister Marcin Kierwiński added that a separate train was damaged on the Świnoujście-Rzeszów route, halting 475 passengers about 50 kilometers from Lublin, though no injuries were reported.

Polish authorities have detained dozens over suspected sabotage and espionage since Russia’s full-scale invasion of Ukraine in February 2022, with some incidents blamed on Moscow. Deputy Interior Minister Maciej Duszczyk cautioned against assuming Russian involvement in every case, though he said it cannot be ruled out.

Tusk pledged that “Poland will catch the perpetrators, whoever they are,” emphasizing the government’s commitment to securing vital infrastructure.