Police said they had discovered a suicide note and were investigating the three incidents but did not give any further details. Photograph: (AFP)
A second separate explosion caused a fire in a nearby parking lot while the man's home, 8 km from the park, burnt to the ground
A retired soldier blew himself up in a park in the Japanese city of Utsunomiya, killing himself and injuring three other people in an apparent suicide, state broadcaster NHK reported, according to news agency Reuters.
Reuters also said a second explosion, separate from the blast that killed the former self defence force member, caused a fire in a nearby parking lot.
Meanwhile, the 72-year-old man's home 8 km (5 miles) from the park was also burnt to the ground, Reuters further added.
The police said they had discovered a suicide note written by the man and were investigating the three incidents, but did not give further details, reported Reuters.
Images broadcast by NHK showed two burnt out cars, one of which belonged to the dead man, about 200 metres (650 feet) from the park and a charred broken bench at the edge of the park, where a folk art festival was underway.
The explosion in the park injured two men aged 64 and 58, who were being treated for shrapnel wounds. The third victim was a 14-year-old schoolboy, Japan’s state broadcaster reported.
(With inputs from Reuters)