explosion in UtsunomiyA
© JIJI Press / AFPParking lot after an explosion in Utsunomiya
At least two nearly simultaneous blasts rocked the Japanese city of Utsunomiy north of Tokyo on Sunday. One was caused by an elderly man who blew himself up in an apparent suicide, injuring three people in a park where a festival was underway in the process.

A camera at NHK broadcaster's Utsunomiya station recorded the sound of several explosions taking place one after another at around 11:30am local time. An aerial shot from an NHK helicopter shows two burned cars parked next to each other in the parking lot, one of which belonged to the 72-year-old retired soldier. Police say they discovered a suicide note written by the man.

Kyodo news agency said his burned body was found in Utsunomiya Joshi Park after police received a call reporting that a person had been engulfed in flames following the sound of a blast.

A note found in the badly burned victim's clothing included the name of the former Self Defense Forces officer, NHK said, adding that his house, had burned to the ground earlier on Sunday.

explosion site in Utsunomiya, Japan
© Kyodo / ReutersExplosion site in Utsunomiya, Japan
The explosion injured two men, aged 64 and 58, who were treated for shrapnel wounds, while the third victim was a 14-year-old boy, NHK said.

One witness told NHK that he had heard a loud noise and saw three people lying on the ground, one behind a bench, noting that he had smelt gunpowder.

"I felt a severe shock wave that seemed louder than a gas cylinder exploding," he told NHK, adding "there was one small explosion followed by a bigger one."

Another explosion, separate from the one that killed the former soldier, caused a fire in a nearby parking lot.

Police are investigating whether there is any connection between the blasts.

Japan's suicide rate is among the highest in the world. Around 30,000 people take their own lives per year, some of whom are retirees pushed to suicide by small pensions.

In 2015, a 71-year-old man set himself ablaze on a bullet train in an incident that also claimed the life of a 52-year-old woman traveling in the same car, Reuters reported.