TORONTO (Reuters) - Polar bears are preying on a group of Beluga whales trapped by shifting ice in the Canadian Arctic, ripping off flesh as the whales surface to breathe, the Canadian Press news agency reported on Monday. It said a hunter first noticed in late April that about 50 whales were trapped under ice near Ellesmere Island, 1,000 km (620 miles) north of the Arctic Circle. The nearest open water was about 30 km (18 miles) away, too far for the whales to find by sonar. It quoted Const. Brian Glover of Royal Canadian Mounted Police as saying the whales had been using a single hole in the ice to surface and breathe. „They‘ve just been coming up to the same hole over and over,“ Glover said. „The bears have been waiting there and jumping on top of them and going for their heads or their blowholes. A lot of them are quite damaged, quite scarred,“ he said. „There‘s huge chunks of flesh taken out of the backs of the whales.“ He said many of the whales had been so badly wounded that the bears could pull them out of the water and onto the ice. Local hunters and trappers had since punched five more holes in nearby ice, giving the whales other places to breathe and a greater chance of avoiding the bears. Glover said up to 13 polar bears had been seen at one time at the edge of the ice, waiting to pounce on the whales. Beluga whales, also called white whales, are common in the area but hunters had not seen such a large group trapped since the 1960s, he said. The ice was starting to break up and the remaining whales should soon be able to get away from the bear ambush. „Nothing can really be done about it. You have to let Mother Nature take its course,“ Glover said. Belugas are one of the smallest whale species found in Canadian waters.