TOKYO — A small explosion damaged a public toilet on the grounds of a contentious Japanese war shine on Monday, drawing police bomb squad technicians and firefighters to the scene and prompting the shrine to close some areas to visitors, the Japanese news media reported.

There were no reports of injuries at the shrine, Yasukuni, which has long been the focus of political tensions. It honors Japanese leaders convicted of war crimes by Allied tribunals after World War II, along with millions of common soldiers and sailors killed in that conflict and others since the 19th century.

Television news showed fire trucks and police vehicles gathered near the shrine’s southern gate, and bomb squad members donning protective gear.

The authorities received an emergency call around 10 a.m. from a visitor reporting a loud bang and smoke emanating from the men’s side of a public restroom just inside the gate, the news media reported. Several outlets said batteries and a pipe, possibly from a pipe bomb, were found inside.