OAKLAND -- A man was wounded by a shotgun blast Thursday morning in a North Oakland park, police said.

The shooting happened at 6:02 a.m. on the baseball field at Golden Gate Park in the 6200 block of San Pablo Avenue.

Police said a 49-year-old Oakland man was walking in the outfield area when he was confronted by another man who shot him in the lower back, buttocks and legs as he tried to run away.

The gunman then fled.

Police said the man's girlfriend happened to be across the street at a gas station and drove him to a hospital, where he was in critical but stable condition.

Police have not ruled out the possibility the shooting was gang-related.

Police and Crime Stoppers of Oakland are offering up to $5,000 in reward money for information leading to the arrest of the gunman. Anyone with information may call police at 510-238-3426 or Crime Stoppers at 510-777-8572.