UPDATE 11am​

Gwent Police have released more pictures from the scene.

UPDATE 8.25am

A spokeswoman for Gwent Police said the two drivers were taken to hospital following the crash.

She said: "At approximately 2:25am on Wednesday,September 20, we received reports of a crash on the A40, Monmouth towards Raglan.

"The incident was between a van and a lorry, the drivers were treated for non-life threatening injuries and were taken to Nevill Hall Hospital.

"The road was closed while recovery work took place, but has since reopened."

UPDATE 8.20am

The road has now re-opened, but there is still long delays.

6.10am

THE A40 is closed southbound due to a "serious" crash.

There has been a crash between a lorry and a van, which have overturned.

The road has been closed since 3am between Cinderhill Street and the A449, affecting traffic heading towards Raglan. 

Traffic is heavy and drivers are being advised to plan ahead for rush hour.

A spokeswoman for South Wales Fire and Rescue service confirmed they attended to the crash.

She said that crews from Malpas and Monmouth attended and that, when they arrived, they didn't have to provide assistance getting anyone out of the vehicles.

She wasn't able to confirm whether someone had been taken to hospital.