Drivers have been warned to avoid the Clyde Tunnel following a serious crash involving a First Bus.

The bus is believed to have struck a barrier and mounted an embankment at the side of the A739 shortly after 7pm on Sunday.

Police and fire crews are on the scene and the road is likely to remain shut northbound for some time. Drivers have been urged to avoid the area.

It is unclear whether anyone was injured in the crash but the bus is believed to have been carrying passengers and police described the incident as "serious".

A Police Scotland spokesman said: "We are currently dealing with a serious road traffic collision at the Clyde Tunnel.

"There are a number of nearby road closures. Emergency services in attendance & the road will be closed for some time.

"Please avoid the area. We will provide updates when we can."

A spokeswoman for the Scottish Fire and Rescue Service added: "We were alerted at 7.08pm on Sunday to reports of a road traffic collision involving a single decker bus.

"Operations control mobilised a number of fire engines to the A814 slip road near the Clyde Tunnel.

"Crews currently remain on the scene working with their emergency service partners to make the area safe."