No children or teachers are among the dead, the Fengxian government said on Weibo, a Chinese social media platform similar to Twitter. Classes were underway when the incident happened, the government said.
The blast occurred in front of the gate of the Chuangxin Kindergarten at about 4:50 p.m., according to Fengxian police.
“The police and related departments rushed to the scene as soon as it was reported and conducted rescue and investigation work on the site,” police said on Weibo. “Currently, the investigation work is still underway.”
Authorities have not said what caused the explosion.
A child with a bloodied face, stumbling back and forth in only her underwear, could be seen surrounded by children splayed out on the ground.
Fengxian is in eastern China’s Jiangsu province, about 370 miles (595 km) northwest of Shanghai.
It’s home to 1.2 million people, according to the government’s website.