MIDLAND CITY, Ala. - Police with SWAT teams and negotiators are at a rural property in Alabama where a man was believed to be holed up in a bunker after fatally shooting the driver of a school bus and fleeing with a 6-year-old child passenger.

Authorities say the shooting happened on the school bus Tuesday and the standoff continued early Wednesday.

Dale County Sheriff Wally Olsen told WBMA-TV the man boarded the stopped school bus in the town of Midland City and shot the driver when he refused to let the child off the bus. The driver later died of his wounds. His identity wasn't released.

County coroner Woodrow Hilboldt told The Associated Press the suspect was believed to be in an underground shelter on his property.