UPDATE 4.21pm

UPDATE 4.09pm

A Gwent Police spokeswoman said: "At approximately 2:10pm, Gwent Police were called to reports of an incident on the M4 near J23.

"A vehicle was located and was found to be carrying approximately 11 people and a baby.

"Officers are carrying out checks to establish the immigration status of those individuals.

"All 11 have been arrested on suspicion of immigration offences at this time. "

UPDATE 4.06pm

Traffic Wales have said that the traffic is now clear. 

UPDATE 3.52pm

Traffic Wales are describing it as a "serious police incident".

They're saying it's affecting the M4 westbound between the toll booths and J23.

2.45pm

THE Second Severn Crossing is blocked, reportedly after a lorry carrying refugees was stopped.

Drivers at the scene say traffic is not being allowed through tolls at this time.