VICTORIA -- Oceanside RCMP are investigating after a loaded firearm was seized from a truck that had crashed off Highway 19, with the driver nowhere to be found.

Police say they first received a report of a single-vehicle collision near Horne Lake Road off Highway 19 around 5 p.m. Sunday.

Multiple witnesses told police that the vehicle, travelling northbound, had crossed the highway's centre median and rolled onto its roof, landing in the northbound lanes.

The driver and an occupant of the truck, a man and a woman, then allegedly mounted a dirt bike that was in the back of the truck and rode away from the scene.

Both people appeared to be injured, witnessed told investigators.

The pair were last seen travelling northbound on Highway 19 and then onto a trail system on a green dirt bike. Police say the same dirt bike was later found crashed.

Mounties say they were unable to find the pair on Sunday, despite a large search of the area with police dogs.

Meanwhile, investigators found a loaded firearm inside the truck, and learned the vehicle had been stolen out of Comox on March 11.

"The fact that we have taken a gun off the street is good news, however the fact that these two were allegedly in possession of it, makes it important now to identify them," said Sgt. Stephen Rose of the Oceanside RCMP in a release Tuesday.

"We are asking anyone with information about the driver or passenger, or (who) was a witness and has not already spoke to us, to please call the Oceanside Detachment."

The Oceanside RCMP detachment can be reached at 250-248-6111.