A lane has been closed on the M1 after a four-vehicle crash.

Hertfordshire Constabulary has confirmed one lane has been closed after a crash involving four vehicles on the south-bound M1, between Junction 7 and Junction 6a at 3.50pm this afternoon.

Lane 1 and the hard-shoulder have been closed.

An ambulance crew and a rapid response vehicle has been sent by ambulance chiefs to the scene and paramedics are assessing people invovled in the crash. 

The road had been completely closed, but officers confirmed they were able to open three of the lanes on that stretch of road.