A policeman was mown down by suspected drug dealers as they escaped arrest in their car.

Their Ford Escort reversed at speed, an open passenger door clipping PC Richard Kempshall and sending him sprawling to the ground.

The metallic-blue car continued reversing and hit 17 parked vehicles before police lost sight of it.

An ambulance was on its way to the scene when a second officer made a dramatic arrest in Cobden Road, Brighton.

One of the men had fled the car on foot. Acting Sergeant Mark Baker chased him for several hundred yards before pinning him to the pavement outside the Cobden Arms pub.

David Belgrove, who lives nearby, said: "I heard shouting and opened my front door. The officer looked absolutely exhausted as he caught the suspect.

"He asked me for help and told me the lad had run over one of his colleagues. My wife Kim telephoned the police.

"The officer turned the suspect's pockets out and there were bundles of money and three mobile phones that kept ringing.

"The policeman said he was arresting the lad on suspicion of drug dealing.

"He kept him pinned down until other officers arrived.

"It was like something out of The Bill."

The drama began at 3.20pm yesterday as children were walking home from schools in the Elm Grove area.

Three plain clothes police officers on foot tried to move in on the Escort in Southampton Street, Hanover, Brighton.

It suddenly reversed towards them, hitting PC Kempshall, and continued reversing into Scotland Street, hitting parked cars.

At one point the car's open passenger door was ripped off.

The Sussex Police helicopter hovered overhead as police continued the search.

Cobden Road was cordoned off and officers scoured the streets looking for drugs believed to have been dropped by the arrested man.

A 17-year-old Liverpudlian was being questioned by detectives today.

PC Kempshall, in his 20s and based at Brighton, joined Sussex Police in 2001.

Chief Inspector Lisa Pearcey said: "He is a very pro-active and popular officer. Thankfully, he was not too seriously hurt.

"Richard and his colleagues were in plain clothes and on an operation likely to result in arrests.

"They made a reasonable assessment of the situation before taking action.

"Their suspicions were borne out by the fact the car driver refused to stop."

Ms Pearcey also praised Mr Baker and the third officer, PC Richard Dugan.

She said: "We are very pleased with their work. It was a team effort from officers."

X-rays showed PC Kempshall did not suffer a broken leg and he was later allowed home from hospital.

Police last night found the Escort which had been abandoned in Brighton.

They were still searching for the second suspect today.

The incident sparked memories of the death of PC Jeff Tooley, who was killed by a hit-and-run driver as he carried out speed checks in Brighton Road, Shoreham, in April 1999.