Three people were injured in the Japanese city of Utsunomiya after an elderly man blew himself up in a local park Sunday. Local police recovered a suicide note written by the man who was reportedly a retired soldier.

Those injured are two men aged 64 and 58 and a 14-year-old boy, according to reports. The deceased was a former member of Japan’s Self-Defence Forces (JSDF).

Another explosion occurred in a nearby parking lot and the 72-year-old man’s house — located within five miles of the park — was reportedly burned to ashes. Officials have launched an investigation into the three incidents.

A folk art festival scheduled at the park was called off following the explosions.

The JSDF was set up in 1954 and comprises of the military’s ground, maritime and air forces.

Recent years have seen a decline in suicide rates in the country. However, they reportedly remain among the highest in the world, with about 30,000 people a year committing suicide. Financial issues such living on small pensions have been blamed for the suicides.