Emergency services scrambled to the scene after the collision occurred, which took place earlier this morning. Firefighters were forced to remove the roof of a car to free a casualty. The driver was then handed into the care of paramedics, but his injuries are not believed to be life-threatening.
Kent Police has confirmed that four vehicles were involved in the collision.
Witnesses also reported an air ambulance at the scene.
When the incident first occurred, all lanes on the M2 westbound between Chatham and Rochester were closed.
While all traffic lanes since reopened, drivers can still expect severe delays.
A spokesperson for Kent Police said: “Kent Police was called at 10.09am on Thursday 9 December 2021 to a report of a collision involving four vehicles between junction 3 and 2 of the London-bound carriageway.
“Officers are at the scene along with other emergency services, and injuries have been reported which are not believed to be life-threatening.
“A road closure is currently in place while the incident is attended to.
“Motorists are advised to avoid the area.”
“Emergency services are in attendance. Please approach with caution.
“Delays are building in the area. More details to follow.”
Diversion routes were put in place to ease the congestion.
Londonbound traffic was diverted towards the Walderslade roundabout complex, then heading onto the A229, M20 and A228 before rejoining the M2 at J2.