(DETROIT)- Traffic across the Ambassador Bridge, the U.S.-to-Canada span from Detroit to Windsor, Ontario, was closed for hours while authorities checked out a bomb threat.
The threat came Monday night to the U.S. side of the bridge.
There was a similar threat four days earlier to the nearby Detroit/Windsor tunnel.
Detroit police say someone called 9-1-1 around 7:20 p.m. Monday, saying a bomb would go off in 10 minutes.
Sgt. Eren Stephens says the call prompted authorities in Detroit and Windsor 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.