XUZHOU, China — An explosion outside a kindergarten in eastern China killed at least eight people and injured nearly 70 on Thursday, leaving a chaotic scene as dozens, some clutching children, were thrown to the ground.

Images of dazed and injured people outside the Chuangxin kindergarten on the outskirts of Xuzhou, a large city in the province of Jiangsu, circulated on Chinese social media. One video showed what appeared to be doctors trying to revive a toddler covered in blood.

In a video posted on Weibo, the Chinese equivalent of Twitter, a man yelled, “Now they are carrying out dead bodies!”

By Friday morning, the Feng County government in Xuzhou said 65 people had been hurt, including eight with serious injuries, in addition to the eight confirmed dead. Two of the dead perished outside the brightly painted building and the other six died later.

The mayor of Xuzhou, Zhou Tiegen, told reporters that none of the casualties were from the kindergarten.

“We’ve checked and at the time of the explosion, the Chuangxin kindergarten still hadn’t been let out of class, and none of the children or teachers from the kindergarten was a casualty,” Mr. Zhou said, according to the website of Legal Daily, an official Chinese newspaper.

Mr. Zhou said that the police had “made an initial determination that this is a criminal case, and are tentatively focusing on a suspect.” But his wording left unclear whether investigators believed that the explosion, which occurred shortly before 5 p.m., was deliberate or caused by negligence.

Hospital workers in Xuzhou said in interviews on Friday that most of the people injured outside the kindergarten were parents or grandparents who were waiting to pick up students at the school.

But at least some of the people waiting at the entrance to the school apparently had toddlers with them.