The nature of the blast is not clear, but an official at the police station in Fengxian county said that the explosion was under investigation.

At least seven were killed and another 59 injured in an explosion that struck a kindergarten in eastern China, according to state media. The blast struck at 4:50 pm local time on Thursday in Fengxian in Jiangsu province.
Photos purportedly from the scene and posted to social media showed children and adults lying on the ground, some of them bleeding.
The nature of the blast is not clear, but an official at the police station in Fengxian county said that the explosion was under investigation.
BREAKING: Blast occurs near kindergarten in Fengxian County, east China, casualties unclear pic.twitter.com/ZhZs1qZGma
— China Xinhua News (@XHNews) June 15, 2017
Kindergartens in China have been targeted before in apparent revenge attacks carried out by people bearing grudges against their neighbours and society.
China maintains tight control over firearms and most attacks are carried out using knives, axes or homemade explosives.