Leftist rebels bombarded a remote police station with makeshift mortars during a six-hour attack in northern Colombia early Wednesday, killing at least 15 officers, authorities said.

The assault in the village of Tierradentro, 230 miles northwest of Bogota, began about 3 a.m. and devastated nearby homes.

Authorities blamed the attack on the Revolutionary Armed Forces of Colombia, or FARC, Latin America's largest rebel group.

"The latest report I have is that there are 15 dead police, between 10 and 12 missing police and four civilians injured," said Jairo Lopez, the top security official for Cordoba state, where the attack occurred. "There were approximately 450 guerrillas."

Lopez said the army was securing the zone.

The raid is the bloodiest since President Alvaro Uribe's re-election in May and comes two weeks after Uribe called off talks with the FARC over a possible prisoner swap, blaming the rebels for a car bomb that injured 23 at a military base in Bogota.

The FARC, which has been fighting the government for more than four decades, released a statement Tuesday night reaffirming its desire for a deal with the government.

The Tierradentro police station was recently constructed on orders of the president, responding to fears by residents that rebels were preparing a campaign in the region.

Colombia's far-right illegal militias controlled much of northern Colombia before their demobilization as part of the peace accord with the government. Residents in many of these zones have expressed fears that leftist rebels would move to fill the power void.

The FARC has unleashed a series of attacks across rural Colombia in recent days, setting off car bombs and downing electrical towers.