By Jeremy McDermott BBC News, Colombia

Farc rebels have been fighting the government for decades

Human Rights Watch says more than 1,000 people were killed by anti-personnel mines in Colombia last year, up from less than 300 in 2001.

The Farc rebel group often places landmines in civilian areas.

The group said the number of civilian victims had increased from 66 in the year 2000, to more than 300 last year.

Child victims

Every day, Marxist guerrillas battered by the US-backed security forces are sowing more home-made mines, known as foot breakers.

The guerrillas have perfected the production of these mines using household items like PVC piping and syringes with the rubber taken out, which act as plungers.

It means the mines can be made for as little as $15 (£7).

Human Rights Watch has detailed the damage inflicted by these weapons, not just on the security forces but on civilians, especially children who play in the woods and jungles near their home and trigger the explosives.

More than three victims a day were registered last year, making Colombia the country with the most landmine victims in the world.

Driven into their mountain jungle strongholds, the guerrillas now protect their encampment drug laboratories and movement corridors by scattering mines.

Few maps are made of where the mines are laid, and since the home-made varieties contain very little metal, they are extremely difficult to detect and so sensitive that even sniffer dogs can detonate them.