Police have arrested 12 men suspected of being involved in international drug trafficking networks in Britain and Colombia.
More than 100 officers conducted a series of "pre-planned, synchronised" dawn raids on 19 houses across London and Kent, the Metropolitan police said in a statement.
"Today's arrests are the culmination of a two-year intelligence-led operation ... into three criminal networks, one Colombian, and two London-based," the statement said.
The investigation is understood to be a spin-off from Operation Anuric — an investigation into a massive international drug smuggling empire, believed to have been one of the biggest ever to have operated in Britain.
Over the course of a decade that cartel was suspected of smuggling hundreds of millions of pounds worth of cocaine into the UK.