Two climbers were killed Friday and two injured when a five-person climbing team from Poland plunged into a glacier crevice on Austria's tallest mountain, police said, according to dpa. The team, consisting of three men and two women, were attempting to scale the 3,798-metre Grossglockner mountain when the accident occurred. The cause of the accident was not immediately known, a police spokesman in the south-eastern city of Klagenfurt. Police said that the team suddenly plunged into a glacier crevice some 400 metres below the Erzherzog-Johann alpine hut, which itself is located at 3,454 metres. Austrian alpine rescue teams rushed to the scene, using four helicopters and evacuating the two seriously-injured climbers to regional hospitals. There were no immediate details regarding the identities of those killed and injured. A police spokesman said the accident was a mystery. "I have never before seen it that all five members of a rope team can plunge into a crevice," the policeman said. The accident comes amid a sharp rise in accidents involving climbers and mountain trekkers in the Austrian Alps during the past several weeks. Statistics published Friday showed that during the past eight years, some 1,400 people had been killed in various recreational acitivities in the Austrian Alps.