University officials decided to evacuate students off a mountain after a brown bear attacked their teacher and they feared the animal had returned.

Students reported hearing a bear within 200 yards of the helicopter that was taking their badly injured assistant professor, Forest Wagner, off the mountain, officials said.

Officials haven't been able to confirm a bear was in the area, but a state trooper hiked in to provide security as the group was flown off the mountain.

The details were among few to emerge since Wagner, a University of Alaska Southeast assistant professor, was mauled Monday as he led the mountaineering class outing in the wilderness near Haines, a remote town about 90 miles north of Juneau.

Wagner, 35, is recovering at an Anchorage hospital and has declined interview requests.

The nine students and two teaching assistants who were with him on the outing returned to Juneau on Tuesday but said they were tired and not yet ready to talk about what happened.

It's unclear if any of them witnessed Wagner's tangle with the bear sow, officials said. The animal had at least one cub with her, according to a university statement.

"It sounds like (Wagner) was kind of hiking ahead, trying to find the best way down," Fish and Game biologist Stephanie Sell told The Associated Press on Wednesday

Alaska State Troopers spokeswoman Megan Peters had no details on the extent of Wagner's injuries. But an internal troopers report obtained by the AP indicated Wagner had extensive leg injuries. The Washington Post first reported details from the internal report.

The group was at roughly 2,000 feet in elevation when the attack occurred, Sell said.

Brown bear dens are common at higher elevations. Fish and Game employees see them in the 2,000- to 3,500-foot range during their bear surveys of the Haines area, Sell said.

"It's a very remote location in great denning habitat," she said.

A student hiked into cellphone range to report the attack, but it took several hours to get Wagner from the mountain to the hospital.

He was transferred between two helicopters before he was taken to Anchorage, roughly 500 miles away.

University Chancellor Rick Caulfield was waiting at the Juneau ferry terminal when the students arrived Tuesday night.

Caulfield arranged to evacuate the students from the mountain after a bear was spotted in the area where a helicopter was attempting to airlift Wagner from the mountain, according to the internal trooper report. A trooper provided security until the group left.

Caulfield said administrators will make sure the students get counseling if they need it. He said one of the concerns is that the trauma could interfere with their end-of-semester finals, scheduled to begin next week.