The M1 northbound is closed between J21 for M69 and 21a. Eleven people are being treated for injuries.
Delays of around 45 mins are expected and the queue is currently over 5 miles long.
A car and a van are reported to have collided earlier this afternoon.
Police, East Midlands Ambulance, and Traffic Officers are all in attendance.
Leicestershire Fire and Rescue Service said five vehicles are involved; three cars, a mini bus and a lorry.
Firefighters confirmed that while there are eleven casualties at the scene with "varying degrees of injuries" being assess by ambulance crews, no one was trapped.
Leicestershire Police said:
"We are currently dealing with a police incident and a road closure is being put in place. Please avoid the area and seek alternative routes. Updates to follow."
The latest statement from Highways England said:
"If travelling in #Leicestershire this evening please be aware there are long delays on the #M1 between J21 (#M69 #Coventry) and J21A (#A46 #Leicester). There are 5.5 miles of traffic on approach northbound which is likely to add 60 mins to your journey time. Plan ahead."
The #M1 northbound #J21 (#M69 #Coventry #A5460 #Leicester) to #J21A (#A46 #Leicester) 3 lanes have been closed due to a serious collision. @LeicsPoliceRPU @EMASNHSTrust & Traffic Officers are currently at the scene.@ATCLeicester
— Highways England (@HighwaysEMIDS) August 12, 2021
The AA's traffic map is saying:
"All traffic is being temporarily held and there is stationary traffic due to an accident. A car and a van is involved on M1 northbound between J21 M69 (Leicester) and J21A A46 (Leicester North / Kirby Muxloe).
"At around 5.35pm, all traffic was held. Lanes two, three and four (of four) were initially closed."
More to follow...