A serious crash involving a tanker, a van and several cars has closed the westbound carriageway of the M4 in Cardiff.
The tanker hit the central reservation halfway between junction 32 for Coryton and junction 33, Cardiff West, at about 17:50 GMT on Monday.
The motorway is closed between junctions 32 and 33 and one lane has also been closed on the eastbound carriageway.
There are long queues in both directions and a diversion has been set up at junction 30.
The Welsh Ambulance Service said it sent two rapid rapid response vehicles, one ambulance and a doctor.
An air ambulance cannot be called in due to the weather conditions.