Up to 30 hungry and desperate bears have attacked and eaten two men in Russia's wild far eastern region of Kamchatka, and have trapped a group of geologists at their remote site.

The bears - apparently starving - killed the men last Thursday, Russian agencies reported. The bears had surrounded a local platinum mining company. Both victims worked at the mine as security guards.

About 400 geologists and miners are now refusing to return to work, afraid of further attacks. Attempts by local officials to fly to the scene by helicopter and shoot the bears have so far failed, because of bad weather, agencies reported.

Kamchatka, 7,500 miles and nine time zones east of Moscow on Russia's Pacific coast, is one of the world's last truly great natural wildernesses. The remote volcanic peninsula is home to the rare Steller's sea eagle, as well as puffins and brown bears, who roam its geysers and snow-covered calderas - collapsed volcanoes.

Kamchatka's 12,000 strong bear population is the largest in Eurasia. Recently, however, the bears have faced unprecedented ecological pressures.

Poaching has led to a dramatic decline in the bear's main food source - the Pacific salmon. Kamchatka is home to a quarter of the world's salmon. But the fish is now disappearing. Poachers have cleaned out entire species by netting rivers. Last year hunters also shot dead at least 300 bears - picking off most of the large ones. At least another 600 were killed illegally, conservationists estimate.

"It's always the bear's fault," Laura Williams, the director of WWF's Kamchatka office told the Guardian yesterday. Speaking from Moscow, she said she was seeking further details of the standoff amid reports that a jeep had been sent to the region to finish the bears off.

About 10 bears have also been seen near the village of Khalino, sniffing fish remains and other garbage, agencies reported yesterday.

Village official Viktor Leushkin told Itar-Tass that a team of hunters would be dispatched to shoot or chase off the bears.

"These predators have to be destroyed," he said, adding: "Once they kill a human they will do it again and again."

Officials from Russia's emergency situations ministry conceded there was too few fish this year or too many bears.

"Either way there is not enough food," an official told yesterday's Moscow Times.

Bears have been known in the past to attack humans in the scarcely populated region. Most humans live in the grey and foggy regional capital, Petropavlovsk-Kamchatky, on the peninsula's east coast. Bears are now encroaching on towns, rummaging in bins and scoffing the remains discarded by food factories.

Officials believe that 100,000 tonnes of salmon are being illegally fished each year.