Two US army soldiers have been injured after encountering a brown bear in a mountainous training area in Anchorage, Alaska, the military said on Friday.

The incident happened on Thursday as the soldiers were participating in a “land navigation training event” in Arctic Valley, part of the Joint Base Elmendorf-Richardson’s training area.

The soldiers were receiving medical care as of Friday, a military official told the Anchorage Daily News. Messages sent to base spokespersons were not immediately returned to the Associated Press on Friday.

The soldiers’ conditions were not released pending notification of relatives.

Both soldiers used pepper spray on the bear, the official said. Few other details were available about the case because it was still under investigation.

“The safety and wellbeing of our personnel is our highest priority,” Lt Col Jo Nederhoed, a spokesperson for the US army 11th airborne division, said in an email to the Anchorage Daily News.

The Alaska department of fish and game is investigating what it says appears to have been “a defensive attack” by a bear that had recently emerged from a den. The area near where the incident occurred has been closed to recreational activity by base officials, the department said.

Samples were collected by investigators with the aim of positively identifying the species and gender of bear involved, the department said.

The base encompasses 100 sq miles (259 sq km) within the municipality of Anchorage, where up to 350 black bears and 75 brown bears roam freely.