Colombian police have begun spraying poppy fields in the south of the country in a new campaign to combat heroin production.

The eradication programme forms part of a multi-million dollar aid package supplied by the United States to help Colombia fight drug-trafficking.

The head of the national police force, General Rosso Jose Serrano, told the BBC that they were using Black Hawk helicopters supplied by Washington, and receiving technical advice from US officials.

He said the aim was to destroy some six-thousand-seven-hundred hectares of poppies in the southern region this year. General Serrano also appealed to European Union countries to try to block the export of chemicals used in the production of illegal drugs. Colombia is the world's biggest supplier of cocaine and a growing source of heroin.

From the newsroom of the BBC World Service