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

Montana's governor has signed an executive order freeing up more resources for law enforcement officers as they search for a former U.S. soldier suspected in a deadly shooting at a Montana bar last week.

Officers are "unrelenting in their pursuit, working around the clock" to find him, Montana Gov. Greg Gianforte stressed at a news conference on Tuesday. "Rest assured, our brave men and women of law enforcement aren’t giving up."