Colombian president calls off peace talks

BOGOTA, Colombia (CNN) -- Colombia's president late Wednesday ended the tenuous, three-year peace process with the country's largest rebel group hours after rebels hijacked a commercial airliner and kidnapped a senator.

President Andres Pastrana said he was ordering Colombian troops to retake the demilitarized zone controlled by the Revolutionary Armed Forces of Colombia, or FARC, the site where peace talks have been taking place.

"I've decided not to continue the peace process with the FARC. I've decided to close the demilitarized zone and I have ordered our troops to return there from midnight," Pastrana said in a nationally televised address.

"We cannot sign agreements with a group that is putting a rifle to the head of innocent people. Colombia says, 'No more. We're tired of guerrilla hypocrisy.'"

The announcement scuttled plans to begin negotiations on peace proposals by FARC and the government, which were to begin Wednesday.

Pastrana made the announcement after meeting all afternoon with the commander of the country's armed forces. A fleet of helicopters and aircraft equipped with night-vision systems were on standby to fly into the zone Wednesday night, sources at the Defense Ministry said.

Earlier in the day, four FARC hijackers boarded a commercial airliner in the central city of Neiva and hijacked it. They forced the plane to land on a rural highway and kidnapped an opposition Liberal Party senator who was on board. The senator, Jorge Eduardo Gechen, was chairman of the Senate Peace Commission.

In a separate incident, FARC guerrillas dynamited a bridge in northwest Colombia that caused an ambulance to plunge into a river, killing four people, including a pregnant woman.

The incidents highlight a war that has lasted nearly four decades. Only last month, international mediators helped Colombia salvage the slow-moving peace process, and warring factions agreed to a strict timetable to discuss a cease-fire in the 38-year-old war.

The sides were supposed to reach a cease-fire deal by April 7, but FARC, in an apparent bid to strengthen its negotiating position, launched scores of attacks across the country.