The three men and one woman were among 33 people arrested and charged in March following a series of 30 raids under Operation Nimrod, an intelligence-led operation targeting drug crime across Lancashire.

Nicola Baldwin, 26, of Elm Grove, was jailed for three years for supplying heroin and cocaine.

Darren Graham, 39, of Maitland Street, was also sentenced to three years in prison for supply of heroin.

Andrew Jessop, 40, of Harrington Street in the city, was sentenced to two years and three months for supplying Class A drugs, to run concurrent to a 12-month sentence resulting from an offence back in February 2008 for affray.

David Jessop, 42, of Duke Street, was sentenced to two years six months for heroin possession.

Paul Burnett, 34, of Porter Street, was given 52 weeks suspended for two years for supplying heroin, and a 12-month supervision order and a nine-month drug rehabilitation order.

They all pleaded guilty at Preston Crown Court.

Ch Supt Pete White, of Preston Police, said: "A significant proportion of people targeted pleaded guilty at their first court appearance which serves to demonstrate the impact and the success of these raids, the biggest in Preston for three years.

"This activity shows our ability to tackle those involved in drug dealing activity and hopefully reassures the community that their concerns are taken seriously."

Also among the targets were six juveniles, who cannot be named for legal reasons, who were dealt with at Preston Youth Court.

A 17-year-old was given 80 hours community service and 12 months supervision.

Another 17-year-old was given a community order of 100 hours and 12 months supervision.

A 16-year-old was handed 70 hours community service and 12 months probation with a curfew between 7am and 7pm.

Two other 16-year-olds were given 40 hours community service and 100 hours community service.

Around a third of the people charged during the operation, which involved months of evidence-gathering on alleged drug dealing, have now been dealt with.

Warrants were executed under the Misuse of Drugs Act on people suspected of being concerned in the supply of Class A drugs in the street or public places, rather than in houses or prearranged appointments - with 125 drugs charges imposed.

Anyone with any information relating to drugs can call 01772 203203 or Crimestoppers on 0800 555111.

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