A shark has attacked a young man in the Russian Far East, biting off his arms in an extremely rare attack in the northwestern part of the Sea of Japan, a report said.
"A 25-year-old man was brought in in grave condition, unconscious. His arms were chewed off at the elbows," the Interfax news agency quoted a source in a hospital in the Khasan district of the Far Eastern Primorye region as saying on Wednesday.
"He'll live," the source added.
A local law enforcement source told Interfax that a shark attacked the man 50 metres off the shore earlier on Wednesday.
"A witness helped the victim to get out of the water and also called rescue workers and medics," it said.
A spokesman for the local branch of the emergencies ministry confirmed to AFP that a "sea animal" attacked a man in the southern Khasan region but declined to provide further details.
Another local spokesman said officials expected to receive more details of the attack after hoping to speak to the man on Thursday.
Following the attack, local emergencies ministry officials toured the area warning thousands of swimmers to watch out for sharks, Interfax said.
Several types of sharks, including the herring shark, can be spotted in the northwestern part of the Sea of Japan but they do not attack people and swimming there is considered generally safe.
The emergencies ministry spokesman told AFP his ministry has never before registered a shark attack on a human in the Primorye region.
Meanwhile a woman vacationing in Puerto Rico was mauled by a shark in the bioluminescent bay of Vieques, requiring emergency surgery for wounds to the leg, officials said on Wednesday.
Lydia Strunk, 27, was bitten by a shark in waters off the Puerto Rican island of Vieques and airlifted to San Juan's Puerto Rico Medical Center, said emergency services official Teudy Martinez.
The bite was around 30 centimetres long from the ankle to knee near the back of her right leg and damaged four tendons of the right foot, but hospital officials said she would be able to walk.
Strunk, a former vice president of Amnesty International's US chapter, will need to remain hospitalised for four to five days, doctors said.
Marine biologist Edwin Hernandez said that the bioluminescent bay, believed to be the largest of its kind, is used by several species of shark for spawning.
"Between May and August there are different species that get into shallow areas, so when females are with the young, they can get a little territorial," he said.
Vieques has become a major tourist destination since the US Navy gave up its testing ground in 2003. The bay has unique microorganisms that create a glow when the water is disturbed.