Two attacks within 48 hours near Vladivostok leave 25-year-old man and boy of 16 with serious injuries

A young man and a 16-year-old boy have been left seriously injured after two shark attacks off Russia's Pacific coast.

Denis Udovenko, 25, lost both arms to the elbow in the first incident on Wednesday in Telyakovsky Bay, near Vladivostok.

Udovenko's wife Polina told a news agency she and her husband had been swimming across a 100-metre stretch from an island to the shore when the predator attacked. "About halfway across Denis noticed something in the water and cried out to me, 'Swim faster, there's a shark'," she said.

Udovenko stopped and grabbed the shark's snout to protect his partner. "He beat it on the nose, and it dragged him up and then down," she said. "Then it threw him up on the surface. A boat pulled up and two lads pulled Denis out of the water."

In the second incident on Thursday, a shark bit into a teenage boy's leg and torso as he swam near Zheltukhin Island, close to the location of the first attack. The boy was being treated in hospital.

Russia's emergencies ministry in the Primorye region closed beaches in the area and called on people to refrain temporarily from swimming elsewhere. It also issued advice on how to react in the event of a shark attack. The victim should try to beat away the assailant, "especially with strikes to the eyes and gills", it said.

Aleksandr Sokolovsky of the regional branch of the Russian Academy of Sciences said sharks had been seen in the area for some time. However, he added: "In the 51 years that I've worked as an ichthyologist in southern Primorye, this is the first confirmed case of an attack on a human."

The shark or sharks involved in the two attacks were most likely great whites, he added.

Some experts suggested the growing presence of sharks in the region might be linked to climate change. Higher sea water temperatures have attracted crabs on which the sharks feed, they said.