A Chinese man has set off an explosion, killing two people, including himself, and injuring two dozen others, state media report.

The man, who is identified as Xie Xingtang, carried out the attack on Monday at a park in Heze, a city in the eastern province of Shandong, according to the official Xinhua news agency.

The explosion also left 24 people wounded, three of whom are said to be in critical condition.

The Xinhua report said the man was a 33-year-old unemployed villager, but did not provide any clear details about the motive for the explosion or the type of the blast.

The People’s Daily, meanwhile, has described Xie as a chronically ill man, whose condition had recently deteriorated.

Two years ago, a street vendor torched a bus in east China’s Fujian Province, killing its 46 passengers and himself. The attack was reportedly staged in retaliation against local authorities.

Also in 2013, a disabled man set off a homemade bomb at Beijing’s international airport to voice his anger at alleged police brutality. There were reportedly no casualties in the bombing, and the suspect received a six-year jail term for the bombing.