An American tourist was airlifted to hospital on Sunday after being attacked by shark in the Bahamas.

The 63-year-old, who has not been named, was attacked on Abaco island shortly after 1pm on August 17, the Royal Bahamas Police Force said in a statement.

The man is believed to have been spearfishing at Big Grand Cay when he was attacked. Police said he sustained severe injuries.

The victim was taken to a local clinic before being airlifted to the United States for further treatment, police said.

The nature of his injuries were unclear from the police statement.