Truck fire near Melbourne's Burnley Tunnel

A truck has caught fire outside Melbourne's cross-city Burnley Tunnel, closing all lanes.

The fire occurred in an emergency left-hand lane outside the tunnel near Southbank on Thursday morning.

VicRoads reported the entire tunnel was closed just before 7.30am, and vehicles inside were exiting via Burnley Street.

One lane reopened about 15 minutes later.

An ambulance spokesman told AAP there were no reported injuries.

In 2007, a truck triggered a multi-vehicle pile up inside the Burnley Tunnel and caused a large fire which killed three people.