A loud explosion has been heard at an outdoor event being attended by Japan's prime minister.
Japanese media claims a pipe-like object was thrown at Fumio Kishida, and it appeared to be a smoke bomb.
It happened shortly after he began a speech at a port in the city of Wakayama - and the leader was subsequently evacuated.
According to NHK, he took cover and remained safe during the incident - and no other injuries have been reported.
One eyewitness told the news channel that she saw an object flying overhead, adding: "It gave me a bad feeling, so we ran away unbelievably fast. Then we heard a really loud noise. It made my daughter cry."
Footage from the scene showed a man being pressed to the ground by uniformed officers as crowds ran away. Police later confirmed that an arrest had been made.
Last July, former prime minister Shinzo Abe - the country's longest-serving leader - died after being shot at close range while making a campaign speech outside a train station.
The assassination shocked the nation and prompted a review of security for politicians.
Mr Kishida was visiting the area to cheer one of his party's candidates, who is taking part in a local election.
