A special anti-drugs unit in Mexico is being disbanded because of corruption within its ranks, Attorney General Rafael Macedo said on Friday.

Mr Macedo said the 700-strong narcotics force, known as Feads, would be shut down and its agents investigated for criminal activities.

"We're going to get rid of these people. They're going to the street or to jail," he told local radio.

The announcement comes a day after soldiers launched armed raids on the unit's offices in 11 of Mexico's 31 states.

President Vicente Fox said the raids were only the beginning, and corruption or involvement in drug trafficking would not be tolerated within Mexico's police force.

Armed crackdown

The force has been linked to illegal activities before, with more than 200 agents already under investigation.

But Thursday's offensive was described as the biggest strike against police corruption in recent years.

President Fox is cracking down on drug trafficking and corruption

Heavily-armed soldiers took control of offices in the states of Sonora, Chihuahua, Tamualipas, Nayarit, Chiapas, Guerrero, Baja California, Oaxaca, Tabasco, Yucatan and Jalisco.

The raids followed the arrest last weekend of seven drug agents in the border city of Tijuana, charged with drug trafficking, extortion and kidnapping.

The seven men were arrested by Mexican soldiers for holding more than four tons of marijuana which had not been registered with the authorities.

The agents had illegally detained two drug smugglers and then offered to free them and return their drugs in exchange for $2m, the attorney general's office said.

Mr Macedo said Thursday's operation was not a reaction to the arrests in Tijuana, but part of a "planned strategy".

"This allows us to start the work of restructuring... with a new special prosecutors' office whose personnel will be subject to previous review and screening," he said.

War against corruption

President Fox's government has already won praise from senior United States officials for its unprecedented co-operation in the war against Mexico's cocaine cartels.

Half of all the cocaine entering the US comes through Mexico, where illegal drug gangs have forged a network of contacts with Colombian producers.

Mr Macedo said that while the president had scored some major successes in his all-out war against corruption, more work was still needed.

"We have to admit there are people who have not understood that this [tolerance of corruption] is over, and we are going to finish with them," he said.