British Petroleum has again drawn the ire of environmentalists after a security guard at one of its Alaskan oil fields shot dead a polar bear, an animal listed as threatened with extinction.
A BP spokesman said the security guard shot the bear on 3 August after it approached employee housing. It did not die until a few days later.
The spokesman, Steve Rinehart, said the guard, employed by Purcell Security, thought he was firing a bean bag round at the bear at Endicott Oil Field on the North Slope. Instead, he shot the animal with a "cracker round," which makes a loud noise and lights like a firecracker.
Authorities in Alaska have begun an investigation, as polar bears are listed as threatened with extinction under the US Endangered Species Act and cannot legally be hunted.
Mr Rinehart said it was the first time a polar bear had been shot and killed on BP's operations in Alaska. He said the guard was trying to protect people, not hurt the bear.
Bruce Woods, a US Fish and Wildlife Service spokesman, said: "We're taking this investigation very seriously."