Fire crews have released three trapped motorists and put out a car fire following a multi-vehicle crash on the M11.
At around 2.15pm emergency services were called to a crash near Sheering, between junction seven and eight.
Emergency services are still at the scene of the collision between three cars, a lorry and a horse box, which contained eight horses.
The Hertfordshire Air Ambulance has taken one person to Addenbookes hospital with serious internal injuries.
Another casualty was taken to hoapital by ambulance with head injuries.
A further two people are being treated at the scene.
Essex Fire and Rescue Service reports eight horses were released from the horse box.
The northbound carriageway is closed and expected to reopen at around 8.30pm with a four mile queue is reported at the exit for Harlow at junction 7.
The southbound carriageway has one lane shut and the Highways Agency reports delays of around 10 minutes.