The Rainbow Bridge was closed to traffic for 2 1/2 hours Thursday as authorities investigated an abandoned car for explosives or bomb-making materials. None were found.
The car was eventually towed away and is being "examined and tested for the presence of explosives residue," customs spokeswoman Christine Pitts said.
"Nothing was in the car. We are still awaiting the test results (for residue)," Pitts said late Thursday.
The international bridge to Canada was closed at 12:15 p.m. as a precaution when the vehicle was found parked at the base of the bridge on the American side, Pitts said.
Bomb-sniffing dogs were said to have found some suspicious substances on the car that led to the alert.
The bridge was reopened at 2:45 p.m. after the car was towed away, city police said.
Further details about the 1988 Plymouth sedan and why agents suspected it might contain explosive materials were not available late last night.