Detroit police say they're investigating a bogus bomb threat that forced the closure of the Ambassador Bridge for several hours.
Monday night's threat was the second such threat to a major crossing connecting Detroit to Canada in recent days.
Police said Tuesday afternoon the investigation was ongoing. No explosives were found in either case.
Detroit police say a 911 call came in around 7:20 p.m. Monday to authorities on the U.S. side of the Ambassador Bridge that links Detroit with Windsor, Ontario. Traffic was halted across the bridge until about 1 a.m. Tuesday.
Just four days earlier, a similar threat was phoned in to Windsor authorities that led to a four-hour closure of the Detroit Windsor Tunnel. A message seeking updated information on that investigation was left with Windsor police.