Beijing: An explosion struck a kindergarten in eastern China while children were leaving the school at the end of the day, killing at least seven people and injuring 59 others, on Thursday.

The blast happened at around 4:50 p.m. at the front gate of the kindergarten in Fengxian County in east China's Jiangsu Province when children were leaving the school. China Global Television Network said that seven people have died and 59 others have been injured in the blast. Two people were killed at the site of the explosion while five died in hospital.

It was not immediately clear what caused the blast, which rocked the kindergarten as parents were picking up children from the school. Pictures and videos posted online showed at least a dozen people lying outside the gate of the kindergarten, according to Hong Kong based South China Morning Post.

Some victims were seen covered in blood while others appeared to be unconscious and some even with their clothes burned off. Children were seen among the injured. "About 5 pm, we heard a blast and thought it might have been a gas explosion at a nearby food vendor," a local shop owner was quoted as saying by online news portal Sohu.

"Many people could be dead," he said. In one video clip posted online, a man covered in blood was seen trying to stand up only to collapse again. His clothes appeared to have been burned off. In a separate video clip, people could be heard shouting: “Blast, blast, dial 110 quickly!”

The gate of the kindergarten appeared to have been horribly bent, with shattered glass littering the scene. China in the past witnessed knife attacks on kindergarten school children by disgruntled people. An explosion of this magnitude was rare.