A 26-year-old man has died of his injuries after being attacked by a shark off a Cape Cod beach in Massachusetts, US.

Arthur Medici, born in Brazil, was boogie boarding with his girlfriend's brother at Newcomb Hollow Beach in Wellfleet about 12 pm when he was knocked off his board and attacked by a shark.

His friend took him to the shore where CPR was performed on him and people at the scene have reportedly tried to make a tourniquet to stop the blood flow.

He was taken to a Cape Cod Hospital in Hyannis where he died, State Police spokesman David Procopio said in a statement.

Police have responded on the scene immediately after the attack.

The details of his injuries have not been revealed. The beach has been closed after the attack.

Medici came to the United States two years ago to attend college, according to WCVB.