SYDNEY, June 6 (Xinhua) -- West Australian (WA) authorities are dealing with yet another shark-related fatality.

A shark is believed to have fatally attacked a 60-year-old female diver off a beach in Perth's north on Sunday.

The shark is estimated to be more than five metres long according to witnesses.

Authorities have issued a kill order for the shark involved in the attack after the WA Department of Fisheries determined "a serious threat to public safety exists," News Corp reported on Monday.

"Given the nature of the injuries and the location of the incident, it is likely that a large white shark, greater than 3 meters in size is responsible," they said.

The 60-year-old's dive partner, a 43-year-old-man, said he felt something brush past him in the water, WA Police Inspector Danny Mulligan told News Corp.

"The man said that he felt something go past him and he turned around," Mulligan said.

"He didn't see the shark at that stage but he felt it better to surface."

Mulligan said that when he surfaced, he saw a commotion in the water.

"Another boat arrived to pull him out of the water and then it was noticed that the lady had suffered some severe and fatal injuries."

The attack comes just days after a man involved in a shark attack at a beach in Mandurah south of the city of Perth last week, died on Friday night following injuries sustained during the attack.