BEIJING — Local government: 7 killed in an explosion at an entrance to a kindergarten in eastern China.

Police say the blast struck at 4:50 p.m. Thursday at the Chuangxin Kindergarten in the city of Fengxian in Jiangsu province.

It wasn’t clear whether the blast was an accident or was deliberately set. The newspaper Xiandaikuaibao on its website cited an unidentified witness as saying the explosive appeared to have been a bottle of cooking gas.

Calls to the kindergarten and local hospitals rang unanswered.

Kindergartens in China have been targeted before in apparent revenge attacks carried out by people bearing grudges against their neighbors and society.

China maintains tight control over firearms and most attacks are carried out using knives, axes or homemade explosives.