The Detroit-Windsor Tunnel has re-opened following a bomb threat that shut down the border crossing for much of Thursday afternoon.

Windsor police said the tunnel was fully-inspected and no suspicious packages were found.

Investigators said they will now turn their attention to finding the individual responsible for the bomb threat.

Traffic on both sides of the border was closed for the police investigation after staff at a nearby duty free shop received a call around 12:30 p.m. indicating there was a bomb inside the passage.

The bomb threat came from the Canadian side of the border, according to police. They believe the call originated from a phone booth in Windsor, but police wouldn’t specify exactly where in the city the call came from. Earlier in the day police dusted a phone booth close to a tourism office by the border crossing

Both the Windsor police explosive disposal unit and the Detroit police K-9 unit spent much of the afternoon searching the scene.

“Because this is an international crossing this is going to be a concern to both the City of Windsor and the City of Detroit,” said Sgt. Matthew D’Asti said earlier in the day.

The 1.5-kilometre tunnel was closed from 12:30 to 5 p.m. and traffic was re-routed to neighbouring border crossings.

The tunnel corporation told CTV Windsor that employees are trained for potential evacuations.

“They practice for this on a regular basis so that they do handle it properly,” CTV Windsor’s Chris Campbell reported.

The Detroit-Windsor Tunnel is the second busiest Canada-U.S. border crossing, following only the nearby Ambassador Bridge. About 27,000 vehicles use the Detroit-Windsor route every day.

With a report from CTV Windsor’s Chris Campbell and Christie Bezaire