Colombia rebels hold 27 hostages

Left-wing rebels in Colombia are still holding 27 employees of the US oil company Occidental Petroleum, despite having released dozens of their colleagues soon after kidnapping them.

Up to 100 Colombian employees of the firm were seized on Monday about 16 kilometres (10 miles) from Arauca in the north-east. They were travelling home by bus from the Cano Limon oilfield, the country's second-largest field.

This seems to be related to the fact that the ELN is manoeuvering in its negotiations with the government

Larry Meriage, Occidental spokesman

An army spokesperson said the released workers were all in good health.

The rebels have carried out mass abductions before to raise ransoms and to force concessions from the government.

A man claiming to be from the National Liberation Army (ELN) called local radio stations admitting responsibility for the mass kidnapping.

Earlier, military officials said a convoy of eight vehicles had been intercepted by ELN rebels dressed as policemen in the east of the country.

Mass kidnappings

The security forces said the release of the hostages followed a hot pursuit.

But the BBC correspondent in Colombia, Jeremy McDermott, says the ELN has a history of kidnapping operations and often selects those victims most likely to bring a high ransom, letting the others go.

ELN rebels are pushing for a safe haven

In 1999 ELN guerrillas hijacked a domestic airliner, forcing it to land on a remote jungle airstrip and kidnapping the passengers and crew.

A few months later, ELN rebels burst into a Sunday church service in Cali, kidnapping the entire congregation and the priest - 150 people in all.

Last year they emptied an upmarket restaurant outside Cali and set out roadblocks nearby, netting some 80 people.

The ELN and the other main left-wing rebel group, the Revolutionary Armed Forces of Colombia (FARC), earn much of their income from ransoms.

The ELN has long targeted the oil industry, believing that foreign oil companies are pillaging Colombia's natural resources.

Safe haven

Occidental said it had not received any direct communication from the kidnappers.

Company spokesman Larry Meriage said they believed the kidnapping was linked with the ELN's drive to receive concessions from the government.

"This seems to be related to the fact that the ELN is manoeuvering in its negotiations with the government during the peace process."

The ELN is pushing for a safe haven, like the one the FARC has, before it begins a formal peace process.

While the government has been dragging its heels for more than two years it is now moving to grant the ELN a demilitarised zone, but is being prevented from doing so by right-wing paramilitaries.

They have launched an offensive in the proposed zone and vowed to do everything they can to stop it.