A surfer has been rushed to hospital after a shark attack at a beach north of Geraldton.

Authorities were called to Glenfield Beach about 9.50am on Monday following reports of a “shark incident”.

A 56-year-old man was found with serious leg injuries and rushed to Geraldton Health Campus, arriving around 10.30am.

A WA Country Health Service spokesperson said the patient was in a serious but stable condition.

The Department of Primary Industries and Regional Development has issued an alert, confirming it is investigating a “reported shark incident at Glenfield Beach”.

“DPIRD is working with local authorities and further information will be provided as it becomes available,” it stated.

Local Jarrad Gray was at Glenfield Beach when he was told about the shark attack.

“We were just having a look out at the beach, and possibly have a look at the fish. And someone just come past in the quad and just said someone ... was knocked off their board by a shark,” he said.

Mr Gray said the news was alarming, but he wasn’t worried for his own safety.

“I don’t now anyway (go much into the ocean). I only go up to my waist and come back out,” he said.

“But I know plenty of people being nudged (by sharks in the past) and things like that.”

A shark of unknown size and species was reportedly spotted 40m off shore at the beach about 9.50am, according to Surf Life Saving WA.

The City of Greater Geraldton has closed a portion of Glenfield Beach, south of the intersection of Glenfield Beach Drive and Surfside Terrace.

“To ensure community safety all recreational water users are advised to avoid the area as the shark may still be in the vicinity,” the city posted on social media.

The public has been warned to take additional caution in the Glenfield Beach area, obey any beach closures advised by local government rangers, Parks and Wildlife Service officers or Surf Life Saving WA.

People can stay informed by checking for shark activity on the SharkSmart website, SharkSmart WA app or follow @SLSWA on X.

If you see a shark, report it to Water Police on 9442 8600.

More to come.