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

Police are looking for Michael Paul Brown, 45, who's wanted for allegedly shooting four people in The Owl Bar in the small town of Anaconda, Montana.

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."