A surfer has been killed by a shark at a popular Sydney beach this morning.

Police said the man suffered critical injuries after being bitten by a “large shark” at Long Reef in Dee Why on the Northern Beaches.

He was retrieved from the surf and brought to shore, but he died at the scene.

Two sections of a surfboard have been recovered and will be examined.

Beaches from North Narrabeen to Manly have been closed, and will remain so for at least 24 hours.

Police will liaise with experts from the Department of Primary Industries to determine the species of shark involved.

The surfer’s identity is yet to be confirmed.

A junior surf competition was being held at nearby north Dee Why Beach at the time.

It is not known if the surfer had any connection to the competition.

A statement from Surf Life Saving NSW said the man was surfing with a group north of the lifeguard tower on Dee Why Beach.

Lifeguards will be keeping people from going into the water.

Drone operators from Surf Life Saving will be scanning the water for any signs of shark activity.

“Our deepest condolences go to the family of the man involved in this terrible tragedy. Volunteers will continue to assist Council and authorities to protect the public from further danger in any way we can,” Surf Life Saving NSW CEO Steve Pearce said.

“For now, please remain clear of the water at beaches in the vicinity and follow the direction of lifeguards and lifesavers.”

Shark attacks in Sydney are incredibly rare, with only one recorded fatality in the past 60 years.

The shark was confirmed later to be a great white.

Prior to that, the last fatal shark attack in Sydney was in 1963.