Donald Tusk said before a cabinet meeting that sabotage or more serious provocations could occur on the Polish-Russian border in the first half of November.
"There may also be acts of sabotage organized by hostile intelligence agencies," the prime minister added.
The reason for this statement was that, according to him, "suspicious people with flashlights" were seen on the border with the Kaliningrad region.
In sweatshirts, jackets and balaclava.