Poland’s prime minister, Donald Tusk, has described an explosion along a section of railway line used for deliveries to Ukraine as an “unprecedented act of sabotage” that could have led to disaster.

There were no casualties from the incident on the line from Warsaw to Lublin, but the consequences could have been catastrophic if the gap in the tracks had caused a train travelling at full speed to derail.

“Unfortunately, there is no doubt that we are dealing with an act of sabotage. Fortunately, there was no tragedy, but the matter is nonetheless very serious,” Tusk said on Monday, after visiting the scene 60 miles (97km) from Warsaw, near the village of Mika.

He described the attack as “an attempt to destabilise and destroy railway infrastructure, which could have led to a rail disaster”.

Tusk said Polish authorities had already launched an investigation into the blast as well as another incident over the weekend that also appeared to involve rail sabotage. “Just like in previous cases of this kind, we will catch the perpetrators, regardless of who their backers are,” said Tusk.

Police said someone had reported hearing an explosion late on Saturday evening but officers performed checks and did not find anything. The damaged section of track was spotted by the driver of a regional train early on Sunday morning, who managed to make an emergency stop before reaching it.

Dariusz Grajda, deputy chief executive officer of Polish State Railways, told Polish television that one of the previous trains had reported an issue with the track, which meant the train that stopped had been briefed on the problem and was travelling slowly enough to stop in time.

The second incident took place near the town of Puławy on Sunday evening, when a train carrying 475 passengers was forced to make an emergency stop after damage to overhead power lines, and a metal brace was found on the tracks. There were also claims of a metal device found on the tracks. No one was injured in the incident, which occurred about 19 miles (30km) from the site of the track explosion.

“According to preliminary findings, windows in one of the carriages were broken … Police officers are conducting investigations at the scene,” the Lublin police department said in a statement.

Poland’s defence minister, Władysław Kosiniak-Kamysz, said the army would inspect the safety of the remaining 120km (75 miles) of track between the incident site and the border with Ukraine.

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The attack comes amid a campaign of sabotage in Poland and other European countries that has been attributed to Russian security services, seeking to sow chaos and discord in Europe over support for Ukraine’s war effort. In Poland, this has included fires and explosions at shopping malls and other sites. Often, the perpetrators are Ukrainians, Belarusians or Polish citizens who are recruited for one-time jobs over the messaging app Telegram.

Security services minister Tomasz Siemoniak said the probability of the acts being carried on orders of foreign intelligence services was “very high.”

He later added: “We are dealing with the [intelligence] services of a foreign state, and not a gang of scrap metal thieves.”

Poland’s interior minister, Marcin Kierwiński, said in a social media post that Poland was “facing acts of sabotage unprecedented in its most recent history.”