By Chris Klint, Channel 2/KTUU.com and msnbc.com news services

ANCHORAGE, Alaska — Possible military aircraft debris, along with material that may be bone fragments, has been discovered in the Knik Glacier area, north-east of Anchorage, according to officials.

Alaska Army National Guardsmen on board a UH-60 Blackhawk flying a routine training mission discovered the debris at about 1 p.m. local time Sunday, and conducted a brief aerial inspection before returning to Joint Base Elmendorf-Richardson.

Capt. Tania Bryan, director of public affairs for the Alaskan Command, said the crash was believed to be that of a vintage aircraft and “not recent.”

She says details about the crash are being withheld pending possible notifications of next of kin.

A recovery effort for the wreckage is being considered by the U.S. Joint POW/MIA Accounting Command, which conducts search, recovery and laboratory efforts to locate lost service members.

The Federal Aviation Administration has placed a temporary flight restriction on the area, and aviators are being asked to avoid the vicinity as personnel investigate the site.

At the request of Alaska military officials, the Hawaii-based U.S. Joint POW/MIA Accounting Command (JPAC) is trying to plan a recovery mission at the Knik Glacier site, a spokeswoman told Reuters.

JPAC, which focuses on search and recovery missions for missing U.S. service members, hopes to schedule an Alaska trip and line up necessary expertise to work on the glacier, said Captain Jamie Dobson, a spokeswoman for the command.

“We believe that there’s a reason for JPAC to be involved,” she said.

Reuters contributed to this report. Channel 2/KTUU.com is an affiliate of NBC News.