The manhunt for the person who opened fire and killed four people at a Montana bar stretched into its fourth day Monday.

The search for a former U.S. soldier suspected of killing four people at a bar in Montana stretched into a fourth day Monday, with deputies scouring the mountainous terrain by foot and air after the man escaped in a stolen vehicle containing camping gear.

Four people were killed in the attack inside the Owl Bar in Anaconda, Mont. The authorities are still searching for the suspect, an Army veteran who lived nearby.