Officials said that the dead in Wednesday's fighting included 17 police officers, 11 rebels and a civilian.
The violence comes two weeks after Alvaro Uribe, the president, renewed his commitment to breaking up the Revolutionary Armed Forces of Colombia (Farc), the country's largest and best-armed guerrilla group. Farc has been blamed for the attack.
Jorge Castro, the national police chief, said the police station at Tierradentro, in the northern department of Cordoba, was attacked in the early hours.
He said at least 150 guerrillas used rifles and launched home-made mortars with gas cylinders in the attack on the station, which had 70 police officers.
Tierradentro is 380km north of Bogota.
General Jorge Ballesteros, the head of the Colombian air force, said that he ordered helicopter gunships and low-flying aircraft to the area to capture the rebels.
The region was formerly a stronghold of the United Self-Defence Forces of Colombia (AUC), a right-wing paramilitary group that recently left after reaching a peace agreement with government negotiators. About 31,000 AUC fighters disarmed as part of the peace process, according to the government.
Coca, the source plant for cocaine, is widely grown in the region, and both left-wing guerrillas and right-wing paramilitary forces have financed operations through its cultivation.
The illegal drugs trade fuels the violence that has killed an estimated 200,000 Colombians over the past 40 years.
The attack comes two weeks after Uribe abruptly ended negotiations with the Marxist rebels on a hostage swap and ordered the army to step up operations aimed at rescuing abductees.