Detroit police said someone called 911 around 7:20 p.m. Monday to authorities on the U.S. side of the Ambassador Bridge saying a bomb would go off in 10 minutes.
Detroit police spokeswoman Sgt. Eren Stephens said the call prompted authorities in both cities to halt all truck and car traffic across the bridge. The bridge was reopened around 1 a.m. Tuesday after security sweeps failed to turn up any incendiary devices.
Monday's bomb threat came just four days after a similar threat was phoned in to Windsor, Ontario, authorities that lead to a four-hour closing of the Detroit Windsor Tunnel. No explosives were found.