Police have seized drugs worth an estimated �3m after an armed chase which ended at a motorway service station.

Two men and a woman from Liverpool were arrested when officers shot out the tyres of a getaway car at Cardiff West services on the M4.

We mean business and we will use all lawful and proportionate means at our disposal

Chief Constable Sir Anthony Burden

Two kilograms of heroin were later found in the operation - one of the biggest drugs raids ever launched in Wales.

The seizure on Tuesday was part of Operation Tarian, the anti-drugs initiative involving three of Wales' four police forces.

During the operation - the result of a continuing investigation into the supply of Class A drugs into south Wales - suspects in Newport who were trying to escape drove on to the M4 and rammed pursuing police cars.

Officers responded by firing a "Hatton Round" - a weapon designed specifically to disable a vehicle by deflating its tyres - at the car's wheels.

South Wales Police said no-one was hurt in the incident which it described as the first-ever operational firing of a weapon by the force.

There has been an influx of drugs into the south Wales valleys

It said the Police Complaints Authority was satisfied there did not need to be an investigation into the incident which occurred at Junction 33 of the motorway.

The force's chief constable, Sir Anthony Burden, said: "We mean business and we will use all lawful and proportionate means at our disposal to protect the people of south Wales from these drug dealers."

The drama came after a team of 250 officers from four police forces carried out raids at homes in Newport, south east Wales.

Twenty-five people were arrested, 15 are still being held.

Gwent Police said 10 had been released on bail, pending further inquiries.

Officers from the Immigration Service joined police in the raids in Newport.

Organised gangs

The houses raided were mainly in the Pill area of the city and crack cocaine, heroin, and cash were seized.

Police have been gathering intelligence into the activities of drug dealers in Newport for several months.

The officers from the Gwent, Dyfed-Powys, South Wales and Gloucestershire forces simultaneously struck at 15 addresses as part of the operation, codenamed Corolla.

The raids were aimed at tackling alleged class A drug trafficking after officers had gathered intelligence over several months.

Gwent Police confirmed that some of the people arrested were alleged to have been working as part of organised gangs of Jamaican drug dealers.

Police in Newport said they had been targetting drug gangs which had moved into south Wales from English cities including Birmingham and Bristol, flooding the area with crack cocaine and heroin.

Treatment

Chief Superintendent Kevin Price from Gwent Police said: "Operation Corolla sends an important message to drug traffickers and reinforces the promises made to our communities.

"I plan to meet with community leaders shortly to build on the strength of our partnership."

Earlier this month, the Welsh Assembly Government announced �18m in extra funding for drug abuse treatment services.

Last month, Home Secretary David Blunkett pledged �1m towards Operation Tarian - a police crackdown on drug dealing in south Wales.