Police are dealing with a collision in Watford town centre.

Emergency services have been called to the ring road at the junction of Lower High Street.

The circumstances around the collision are not yet clear but three of four lanes have been shut off by police officers.

Several police cars are at the scene alongside an ambulance.

Some buses are on diversion as a result of the incident.

Traffic is very slow onto the ring road from Waterfields Way towards the junction with Water Lane.

Hertfordshire Constabulary is advising motorists to avoid the area if possible.