Polish police have detained a man suspected of plotting to assassinate Prime Minister Donald Tusk and Defense Minister Wladyslaw Kosiniak-Kamysz.

"The man threatening an attack has been detained," Tusk wrote on X on Sunday, praising police for their "swift and decisive action." Interior Minister Marcin Kierwinski confirmed the arrest.

The suspect is a Polish citizen in his 60s who was arrested in the southwestern region of Lower Silesia, Interior Minister Marcin Kierwinski told public broadcaster TVP Info. The case began when an email about a possible attack reached the State Protection Service, which guards senior officials. The service passed it to police. Security chiefs then held an emergency meeting.

"In this case we are talking about a strong likelihood that these threats could actually be carried out," Jacek Dobrzynski, a spokesman for Poland's special services coordinator, told local media, according to the BBC.

Kierwinski said police found the man by studying what he posted online. He said it was "probably too early" to talk about any foreign link. "It rather appears that this is a man from very radical groups," he said. Police searched the man's home, and his online contacts are being examined.

The arrest came during a tense week in Poland. Three knife attacks at schools left one person dead and many hurt. Tusk blamed the school attacks on the online glorification of violence. Poland, which borders Ukraine, has also faced sabotage and other hybrid attacks blamed on Russia in recent months.

Tusk has led Poland's government since 2023. He was prime minister before, from 2007 to 2014, and later served as president of the European Council.

What we know: Police detained a Polish man in his 60s in Lower Silesia on Sunday over an alleged plan to kill Tusk and the defense minister.
What we don't: The man's name, what charges he will face, and how far any plan had gone.