WASHINGTON, D.C. — The U.S. Customs Service said it’s considering changing its inspection procedures at the Canadian border.

The new method would ideally see terrorists stopped before they cross bridges and tunnels into the United States.

At 13 points of entry along the northern border, people entering the United States are not stopped by U.S. Customs agents until after they cross a bridge or tunnel, according to U.S. officials. This leaves those points of entry vulnerable to terrorist attacks explains Michigan U.S. Senator Carl Levin.

Levin has been pushing the U.S. Customs Service and its Canadian counterparts to conduct “reverse inspections,” where the two countries would set up stations on opposite sides of the border.

Customs Commissioner Robert Bonner and Canadian Customs Commissioner Robert Wright have created a working group to study northern border security, including the possibility of reverse inspections.

Customs spokesman Jim Mitchie said it is not clear whether a reverse inspection system would only be implemented at the 13 bridge and tunnel crossings – located in Michigan, Maine and New York state – or at all 129 points of entry along the Canadian border.

Forms of the system are found at a few Canadian airports but Bonner stated in a letter written to Levin that expanding it to other points would probably require a change in U.S. and Canadian law so the foreign officials would have the authority to operate in each other’s country.