( CNN ) -- A major bridge between Detroit , and Windsor , Ontario , reopened early Tuesday after a bomb threat shut it down for more than five hours , police said . Authorities closed the Ambassador Bridge after a bomb threat was received around 7:15 p.m. , according to Sgt . Eren Stephens , a Detroit police spokeswoman . It finally opened at 1 a.m. after bomb-sniffing dogs `` did not detect or find a bomb or suspicious device . '' The U.S. Coast Guard stopped all maritime traffic below the bridge during the incident . The Ambassador Bridge is the busiest commercial international crossing in North America with more than 10,000 commercial vehicles crossing the bridge on a typical weekday , according to the bridge 's official website . More than 25 % of all commercial goods between Canada and the United States cross the Ambassador Bridge , the website said . The closing followed last Thursday 's closing of the Detroit-Windsor Tunnel , which also was prompted by a bomb threat . CNN 's Rick Martin and Julia Greenberg contributed to this report .
Bomb threat closes the Ambassador Bridge between Detroit and Windsor , Ontario . A Coast Guard spokesman says it is `` too soon '' to determine who sent the threat . A similar threat last week closes the Detroit-Windsor Tunnel .