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

A manhunt is intensifying for the gunman who allegedly killed a bartender and three patrons at a bar in southwestern Montana, authorities said.