A 2.1 metre-long great white shark has bitten a man swimming off southern California’s Manhattan Beach, officials say.

The man was injured on the upper right side of his body about 9.30am on Saturday, suffering puncture wounds described as moderate injuries, a Los Angeles County Fire Department spokesman said.

The man was conscious as he was taken to hospital, the spokesman said.

The incident started when a person fishing off the Manhattan Beach Pier hooked the shark and spent over 30 minutes trying to reel it in, which made the shark grow agitated and take out more and more fishing line.

The victim was in a group of long-distance swimmers about 275 metres off the beach swimming past the pier, where the spokesman said the shark bit the man.

The fisherman cut the line, and a surfer put the injured swimmer on his board.

The victim was taken ashore with the help of Los Angeles County lifeguards and paramedics began treating the man.

The shark remained in the area for the next 20 minutes and then disappeared.

Sharks, including great whites, are common in the area, but attacks are extremely rare, the spokesman said.

“There’s a sighting almost on a daily basis out here,” he said.

The beaches remained open, but a 1.6 kilometre stretch was temporarily off-limits to swimmers.

Lifeguards patrolled in boats to make sure the water was clear.