A 13-YEAR-OLD boy was badly injured by an unknown explosive while playing with his friends in Bao'an District on Sunday night.

It was the second blast caused by an unidentified explosive in Shenzhen within a week. Two boys were killed and one injured in the Shazui neighborhood in Futian District on Wednesday.

The boy, a junior high school student, was playing with a dozen of teenagers in front of a shopping center at 8 p.m. when the accident occurred, seriously injuring his right leg, left hand and face.

"There was a powerful explosion similar to that of firecrackers," said a policeman at the scene. He said it was hard to tell what the unknown explosive was at present but he ruled out it being a bomb.

The scene, in the middle of busy shopping centers, was roped off in case of further explosions.

A witness surnamed Chen said the blast was loud and followed by a strong smell of gunpowder. "I saw a boy covered in blood, and his kneecap was badly hurt," he said.

The victim was sent to the Bao'an People's Hospital soon after the blast, and received surgery to his right leg. He told his parents that the object blew up as he touched it.

Two boys, 5 and 8 years old, died in Futian District after an unknown object they were playing with on the lawn near their home exploded Wednesday. Another 9-year-old was badly wounded in the accident. Police said the suspected object could have been a grenade.

Editor: Yan