Slovakia has expelled two men suspected of monitoring energy infrastructure targets including along a major pipeline carrying gas from Ukraine.
Interior Minister Matus Sutaj Estok said on Monday that security services had dismantled a rogue cell.
The men were deported to Ukraine and Hungary, Sutaj Estok said in a video on Facebook.
Estok said, “We prevented a possible attack on critical infrastructure of Slovakia.”
Slovakia’s government held a meeting of the National Security Council last week to discuss the threat of attacks.
“Members of the security and intelligence forces of the Slovak Republic were able to dismantle a rogue cell that posed a potential risk to our security,” Estok said.
In another video on Facebook, he said, “Police and other security forces are doing their best for the safety of people in Slovakia.”
He said Slovakia had seen similar security incidents in recent years, including damage to the Nord Stream pipeline or arson attacks in the Czech Republic.
He added, “We have taken vigorous and rapid measures to prevent such attacks and are taking other preventive measures to protect our territory.”
Sutaj Estok said security actions centred around activities by two foreigners and a Slovak citizen suspected of planning possible attacks on energy infrastructure.
He did not name any state actor behind the cell or any specific attacks being planned.
The men allegedly used a drone to monitor a transformer station in Velke Kapusany in the east of the country along the Ukraine border.
Estok said that they also used a compressor station for the gas pipeline running there from Ukraine that transports Russian gas.
Other equipment was also discovered, including a number of telephones, notebook, thermal cameras, ballistic vests and other items.
One suspect also used a car at a railway station at the time of loading Slovak army equipment, the Interior Minister added.