Tom Metcalfe reports: "The situation has recently worsened"

It is the latest in a series of protests against the rising number of abductions.

About 50,000 people, wearing white shirts and carrying placards saying "No more kidnappings" took part despite heavy rain.

The BBC correspondent in Bogota says the recent mass abductions by a rebel group, the National Liberation Army, (ELN) have sparked the public outcry.

Fifty thousand say "no more"

But he says despite the protests the kidnappings are unlikely to stop, as the guerrillas are reliant on ransom revenue to continue their struggle.

"The only thing the Colombian people want is to live in peace," said Attorney-General Jaime Bernal Cuellar, who joined the demonstration.

There have been over 1,200 kidnappings already confirmed this year and the head of the government anti-kidnap department said it could be the worst year on record, beating last year's figure of over 2,600.

• In April the rebels hijacked a domestic airliner and kidnapped forty-one people on board

• In May they abducted an entire church congregation in the city of Cali, taking more than one-hundred-and-forty people

• In June an anglers club returning home after a weekend fishing in the Caribbean was intercepted by guerrillas in speedboats - nine were taken

The 30-year-old guerrilla war has taken more than 35,000 lives in just 10 years.