Operation Sledgehammer targeted houses in the Stanley area of County Durham.
Six people were arrested for conspiracy to supply class A drugs, and they are currently being questioned by detectives.
Those arrested included a 33-year-old woman at Blanche Terrace, Tantobie; a 42-year-old man at Tennyson Gardens, Dipton; a 44-year-old at Fourth Street, Quaking Houses, a 41-year-old man at Park Road, and a 37-year-old man and a 30-year-old woman at Poplar Street, both South Moor
Acting Neighbourhood Inspector Dave Turner said: “Today’s action is a result of a long-running, ongoing police investigation which aims to tackle those suspected of being involved in drugs offences.
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“We are determined to dismantle, disrupt and destroy the networks of those involved in drug dealing who blight our communities.”
Anyone with information about drug-dealing in their area can call the police on 101, or call Crimestoppers confidentially on 0800 555 111.