Police cordoned off Warsaw's Pilsudski Square and the surrounding area of the Polish capital on Saturday, with local media reporting that a man had climbed onto a monument in the square and threatened to blow himself up.
Private broadcaster Polsat News reported that at around 1130 GMT the man surrendered to police. Its footage showed him climbing down from the monument, taking off his jacket and walking away with his hands in the air.
The incident came a day before Poland holds a high-stakes parliamentary election.
Bomb threat in Warsaw
A police officer at the scene had told a Reuters reporter: "No entrance, there is a bomb," but a police spokesperson quoted by the state-run PAP news agency did not confirm the reports that the man was threatening to blow himself up.
Footage posted on social media platform X, formerly known as Twitter, had showed a man standing on top of the Smolensk monument, which commemorates the victims of a 2010 air disaster that killed 96 people including President Lech Kaczynski and his wife, Maria.
PAP said several hundred officers were involved in an operation around the square. A Reuters video journalist saw armed officers arriving nearby.
A guest at the Sofitel hotel, which faces the square, said they had been told to only leave the building by the back exit.