At least four people were killed and two others hurt in a shooting incident in the US city of Philadelphia on Monday.

The injured people were 2 and 13 years old.

A suspect was apprehended with an AR-style rifle, a handgun, a bulletproof vest, multiple ammunition magazines in the vest, and a scanner after the shooting that spanned several blocks in or around the Kingsessing neighborhood, Philadelphia Police Commissioner Danielle M. Outlaw was quoted as saying by CNN.

A second person – who may have picked up someone’s gun and returned fire – also was in custody, Outlaw said.

He said the condition of the injured people was stable.

The cause of the shooting is still not known.