A two-vehicle crash has shut down northbound lanes of the Pat Bay Highway at McKenzie Avenue.

A detour was available via the McKenzie Avenue off-ramp, according to Drive BC.

It's unclear what caused the crash but witnesses at the scene reported seeing a vehicle overturned near the off-ramp.

There's no word on injuries or estimated time of reopening for northbound lanes of the highway.

Drivers are asked to use an alternate route in the meantime.