The air ambulance is at the scene of a serious crash involving a lorry and a motorbike which has closed the A12.

The southbound carriageway is closed between the junctions for Colchester Community Stadium and Stanway this morning due to the accident, which took place at around 9am.

A lorry and a motorbike are understood to be involved in the crash. 

One witness said: "It looks like an accident involving a motorcycle.

"The air ambulance is flying around looking for somewhere to land."

He added: "It looked like people were getting out of their cars to help at the scene."

Traffic is queued off the the on-slip at the stadium right along Axial Way.

Long queues on the A12 remain.

The service station and park and ride are almost accessible due to traffic.

Drivers are advised to avoid the area if possible.

A spokesman for Essex Police said: "We understand the collision took place on the southbound carriageway, which is likely to be closed for some time as we carry out our enquiries.

"The northbound road was closed to allow the air ambulance to arrive. Please avoid the area."

Drivers have also been warned not to turn around in the carriageway to try and escape the queues.

The spokesman continued: "We have also received reports of vehicles turning around on the A12 to avoid the traffic.

"This is unacceptable and can put you and others at risk."

A lorry has also broken down in the queues on the southbound carriageway near to Junction 29, the Crown interchange.

Brentwood Live:

Traffic queuing at junction 28 - Colchester Community Stadium.

There are also reports of debris in the carriageway further in the opposite direction and another potential accident on the northbound side.

The road is partially blocked between the junctions at Marks Tey and Eight Ash Green. 

Essex Travel News has tweeted a map showing the delays around Colchester this morning.

Brentwood Live:

More to follow.