New Zealand police have shot at a shark which is believed to be one of up to three sharks involved in the fatal attack on a man at a beach near Auckland.
The 47-year-old man was killed while swimming off Muriwai Beach, about 40 kilometres west of Auckland, about 2pm (local time).
Fisherman Pio Mosie witnessed the attack and says it was like a scene out of a horror movie.
"He just shouted shark. Next minute we saw him rolling around everywhere," he said.
"The first time there was like one shark but all of a sudden, after five or six minutes after that, we saw three sharks all over him, rolling him around.
He told NZ news website stuff.co.nz that he and a friend had been watching the man swim about 200 metres offshore.
"We kept watching [the man] while he was swimming. We saw the fin of the shark, then next minute, boom, it took him," he said.
"There was blood everywhere on the water. I grabbed my phone out of my pocket and dialled 111.
"While he was still alive he put his head up, we called him... he raised his hand up and then while he was raising his hand up, we saw another attack, pulled him under water."
Police Inspector Shawn Rutene says by the time lifeguards and police reached the man he was dead and there were two sharks circling.
"My staff member has taken with him a firearm and he has discharged his firearm towards the shark and we do not know at this stage whether or not he has hit the shark but the shark rolled off and disappeared," he said.
It is likely the three to four metre shark is a great white.
Aerial and beach patrols will monitor Auckland's west coast beaches, which have been closed for two days.
The international shark attack file says there have been 48 known shark attacks in New Zealand, eight of them fatal.