Canberra, Nov 1 (IANS): A search is currently underway for the body of a man who was attacked by a shark while surfing in the state of South Australia (SA), authorities said on Wednesday.

The 55-year-old man was surfing at a beach at Streaky Bay, more than 450 km west of Adelaide on the Great Australian Bight, when he was attacked and dragged underwater by the shark at about 10:20 a.m. on Tuesday, reports Xinhua news agency.

SA Police initially said a person was seriously injured in the attack but later said emergency services were searching for the man's body and the shark.

Jeff Schmucker, a fellow surfer who witnessed the attack from his jetski, said it was a 4.2 meter great white shark that attacked the man from the side.

Schmucker told Seven Network television that he arrived on the scene within 60 seconds of the attack but that there was no sign of the victim.

Another witness, Ian Brophy, described the attack as "gruesome".

"I saw the shark go and just launch and bit over the top of the guy and bite and drag him down under the water and then nothing for a minute or two and blood everywhere and then up pops the board," he told News Corp Australia newspapers.

"I saw him in the wave and the shark had his body in his mouth. It was pretty gruesome."

Emergency services launched an air and sea search for any sign of the man's body or the shark.

It is the third major shark attack in the state of South Australia in 2023.

Grandmother Pam Cook was left seriously injured after being attacked by a juvenile great white shark earlier in October 300 km south of Adelaide at Beachport.

In May, 46-year-old teacher Simon Baccanello was killed in an attack near Elliston, 100 km south of Streaky Bay.

Remnants of Baccanello's wetsuit were found during an extensive search but his body was never located.