BAKERSFIELD, California (AP) -- A military shell given to a group of children by a neighbor exploded while they played with it, killing two children and injuring five others, police and witnesses said.

Police were investigating the cause of Tuesday's explosion, which damaged homes and forced neighbors to wrap bloodied and dazed children in blankets.

"As you can imagine, this was a traumatic experience for the kids and their parents," said Bakersfield Police Detective Greg Terry. "So it's going to take a while to sort things out,"

Andrew Etcheverry, 8, died at the scene, and Jeni Marie Klawitter, 7, died at the Kern Medical Center, the county coroner said.

The victims, the oldest 12 years old, suffered minor to moderate injuries. Police had initially reported that six children were injured but determined that a girl thought to be hurt was not at the scene when it exploded.

Frank Sendejo, who lives near the apartment complex where the explosion occurred, said Wednesday he had given a group of children a 40 mm shell. Police said they have talked with Sendejo.

Sendejo told The Bakersfield Californian that he thought the shell was spent and often used it as a "conversation piece." He said the firing pin and bottom shell casing had been removed, along with the gun powder inside.

"I thought it was harmless," he told the newspaper.