Polish police detained a man on Sunday, 11 October, on suspicion of threatening and planning an attack on prime minister Donald Tusk, interior and administration minister Marcin Kierwinski said.

The threats also targeted defence minister Wladyslaw Kosiniak-Kamysz. Authorities did not say who the man is or what the planned attack involved.

Kierwinski announced the arrest on X at 16:37 local time. Ten minutes later, Tusk posted a message thanking the officers.

"The man who threatened an attack has been detained. I thank the police for their quick and decisive action," the prime minister wrote.

The day in Warsaw began with an alert early in the morning. A warning about a possible threat came in at about 7am local time and first reached the State Protection Service, known in Poland as the SOP. The service then passed the case to the police.

Tusk did not stand by and wait. Before 8:30am local time, he called officials from the security services to a meeting at the Chancellery of the Prime Minister (KPRM). He walked there from his nearby residence under guard, said Jacek Dobrzynski, spokesman for the minister coordinating the special services.

A second meeting began at about 11am local time, this time at the Anti-Terrorist Centre of the Internal Security Agency (ABW). Officials from the police, the ABW, the SOP and other services involved in the case attended.

Two ministers directed the services' work during the day: Kierwinski, who is in charge of interior and administration, and Tomasz Siemoniak, the minister coordinating the special services in the Polish government.

Dobrzynski said that after the meeting at the Anti-Terrorist Centre, the services had found the information credible and alarming. He said there was a high likelihood that the threats would be carried out.

"We are treating this case with deadly seriousness," the spokesman said.

Government spokesman Adam Szlapka called the warning "extremely alarming", meaning the cabinet saw it as very serious.

The authorities did not keep the case quiet during the day. Even before the arrest, they said publicly that there were threats against prime minister Tusk and defence minister Kosiniak-Kamysz. The services said they chose to go public to avoid speculation.

Just over nine and a half hours passed between the first alert in the morning and Kierwinski's post about the arrest. In that time, the prime minister, ministers and several services met twice, and police tracked down the suspect.

Polish authorities have not yet said how the man was found, where he was detained or whether he acted alone.