A U.S. citizen is in custody following a police incident at the Pacific Highway border crossing on Tuesday afternoon.

Surrey RCMP said a vehicle failed to stop at the crossing while heading into Canada at approximately 2:40 p.m. The suspect was allegedly in possession of a firearm at the time.

Witness Cadi Schiffer told CTV News she was at a booth at the border crossing at the time when she heard a commotion followed by several gunshots.

"There was a bunch of yelling and 'pop, pop, pop,'" Schiffer said. "All the border officers perked up and ran over and surrounded a car." 

While the officers were approaching, the vehicle sped off with its trunk open, according to the witness. 

Another witness, from a local gas station, said they saw what appeared to be Mounties chasing a Volkswagen Jetta southbound back toward the border from the Canadian side around the same time.

RCMP said cruisers followed the suspect's vehicle through South Surrey, and were able to stop it as it crossed into the U.S.

The suspect, a U.S. citizen, was then taken into custody without incident. There have been no reports of injuries, RCMP said.

The incident closed the border for approximately three hours as armed police officers and border guards responded, but it was reopened by 6 p.m.

Surrey RCMP are leading the investigation into the incident, in partnership with the Canada Border Service Agency and U.S. Customs and Border Protection.