Farc militants attacked a rural Colombian police command today, killing at least 16 officers in one of the worst blows this year to President Alvaro Uribe's campaign to end the country's 40-year conflict.
The attack is part of a two-week offensive by the Revolutionary Armed Forces of Colombia, or Farc, that has dampened hopes of eventual peace talks with the government.
"We have 16 police dead, three more wounded and two civilians also wounded," a police spokesman said.
The rebels used mortars made from gas-tank cylinders in their attack on the town of Tierradentro in Cordoba province, authorities said.
Government attack helicopters and aircraft were sent to back troops dispatched to control the town. Police and residents said earlier the rebel assault damaged homes near the police station.
The attack was the latest since Mr Uribe pulled back from possible negotiations with the 17,000-member Farc over the release of hostages the rebels are holding, including three US contract workers captured nearly four years ago.
The Farc said last month that a hostage swap could set the stage for peace negotiations.
Mr Uribe, who has led a US-backed crackdown to end Colombia's four-decade-old insurgency, appeared close to possible talks until he blamed the Farc for a car bomb attack at a Bogota military college two weeks ago.
Another car bomb blamed on the Farc in Villavicencio, 70 kilometres from the capital, killed one soldier and a taxi driver outside an army base over the weekend.
Mr Uribe came to office in 2002 with a hard-line promise to defeat paramilitary groups.
Violence dropped after he sent troops to retake urban areas once controlled by rebels and demobilized illegal paramilitaries who once fought the Farc.