Police are appealing for witnesses to come forward after a crash involving a police car trapped shoppers in a supermarket car park for up to three hours.

Tempers flared and rows broke out among drivers trying to leave Asda in Gillingham on Saturday afternoon.

Huge queues built up since the smash at the busy junction in Pier Road at about midday.

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Police were drafted in to break up rows and direct traffic. No one was arrested.

It is thought vehicles were being allowed to enter the car park, but the backlog meant customers could not get out after they had finished shopping.

Officers eventually closed the car park for 20 minutes to stop more vehicles from entering, and the gridlock started to ease just before 3pm.

One driver caught in the chaos said: "There's still problems at Asda, with fights breaking out between irate motorists.

VIDEO: Police car crash causes chaos at Asda Gillingham Pier

"Police are dealing with them. It's only pushing and shoving but I still can't get out of car park! Nightmare.

"It's not moved for ages. We are at gridlock, nothing able to get in or out. Some people have been stuck for several hours. Staff are now trying to manage traffic."

Another posted on Facebook: "Everyone avoid Asda Gillingham if driving, an accident involving a car and police car just off the exit of Asda, but has caused major havoc in Asda car park.

"Hundreds of cars at a stand still in the car park, no one can move!"

A police spokesman said: "Police are dealing with a disturbance at a supermarket in Pier Way, Gillingham. It was reported to police at 2.10pm.

"Extra patrols have been sent to the road after a number of people were reported to be arguing as a result of traffic delays."

At the time of the crash, the spokesman said: "Officers are currently dealing with a collision in Pier Road, Gillingham.

"The incident reportedly involved a police car and another car. South East Coast Ambulance Service have been called to the scene."

The police car was on an emergency call at the time of the crash.

The force's serious collision investigation unit is now looking into it.

It happened within minutes of a separate accident involving an ambulance just a few miles away on the A2 in Rainham.

Kent Police's roads unit tweeted to say no one was injured and the road was not blocked.

A force spokesman added: "Police were called to London Road, Rainham at 11.44am today following a report of a two-vehicle collision.

"No one was reported to have been injured."

Anyone who saw the crash in Pier Road who has not yet spoken with officers is asked to call the serious collision investigation unit on 01622 798538.