Up to 500,000 people have marched through the Colombian city of Medellin, which has population of 2m, protesting against kidnapping in a province traditionally at the centre of the 35 year civil war.

Colombia is the kidnap capital of the world, according to the US State Department, with the majority of abductions being carried out by left-wing rebels for ransom. They use the proceeds to fund their war against the state.

There have been over 1,500 kidnappings already confirmed this year, an average of eight a day. These figures suggest last year's total of 2,609 abductions, the worst year on record, will be easily surpassed.

New tactics

But whilst kidnapping of wealthy Colombians have been going on for decades, the situation has changed over the last year and particularly over the last four months.

The main change as been the new guerrilla ploy called "miraculous fishing", named after Jesus' pledge to turn his disciples into fishers of men.

This involves setting up random road blocks all over the country and netting whoever is unlucky enough to pass through.

The crowds remembered over 1,500 kidnap victims

But April saw the new face of kidnapping - mass abduction. There have been three such operations, all carried out by Colombia's second largest rebel group, the National Liberation Army.

The first in April saw the hijacking of a domestic airliner, forced to land on a remote jungle airstrip. The crew and passengers, 41 in all, were kidnapped.

At the end of May, guerrillas abducted an entire church congregation in Cali including the priest, hurling over 140 believers into waiting trucks.

Then last month, an anglers' club returning home from a weekend's fishing in the Caribbean, was intercepted by guerrillas in speed boats. Nine were taken.

Despite the massive public outcry, the rebels are unlikely to stop because they are reliant on ransom revenue to continue their struggle.