A surfer is missing after being attacked by a shark off Australia's southwest coast Friday, in an area notorious for great white encounters.

The surfer, believed to be a man, was attacked on Friday morning off Kelp Beds beach, near Esperance -- about a seven hour drive from Perth, local police said.

A nearby surfer tried to help the man after the attack but could not pull him from the water, Western Australia premier Mark McGowan told media. "It sounds like it's a very, very difficult and very serious situation going on there at the moment," McGowan said.

The man's surfboard washed-up on shore showing "obvious signs of shark attack" but rescuers were still scouring waters for the surfer, Western Australia Police Force Senior Sergeant Justin Tarasinski told national broadcaster ABC.

"Unfortunately at this point in time, no we've not recovered the surfer that was involved in the attack and the search operations are ongoing," Tarasinski said.

The beach had been busy at the time with about eight surfers in the waves and several more people on shore, he said.

In January a man was killed by a great white at a nearby diving spot and three years earlier a 17-year-old girl was mauled to death at the same beach.

While in 2014, a young surfer lost parts of both arms after being attacked by two great whites, also off Esperance.

There have been six fatal shark attack in Australian waters so far this year, according to Australian Shark Attack File maintained by Taronga Conservation Society Australia.