JACKSON -- At least four grizzly bears have been killed in encounters with hunters in Wyoming this year, according to Wyoming Game and Fish Department bear management officer Mark Bruscino.

All the deaths are under investigation, so the department isn't releasing information including the identities of the hunters or details of the encounters. But Bruscino said no one was injured in the incidents, and all the cases related to elk hunting activity in the area where the grizzlies were killed.

The areas are south of Yellowstone National Park, around Cody and Jackson and the Lander region.

The deaths have occurred since the beginning of elk hunting season, which varies in different regions.

Bruscino said he didn't know if all the cases involved Wyoming hunters. He also said it was unclear when the investigations will be completed.