Just hours after President Andres Pastrana accepted an eleventh-hour accord to salvage Colombia's three-year-old peace process, leftist rebels came out fighting Tuesday.

Guerrillas from the Revolutionary Armed Forces of Colombia, or FARC, exploded bombs in the town of Puente Quetame. They also blasted into a prison and freed 39 suspected rebel members, authorities said.

"While the FARC was expressing their willingness to have peace, they were bombing a civilian town," Defense Minister Gustavo Bell said.

Pastrana had given a U.N. envoy and 10 foreign diplomats until Monday night to convince the rebels to return to the negotiation table. Troops were massed outside the safe haven to retake the zone at his go-ahead.

In order to save the talks and remain in their safe haven undisturbed, FARC rebels agreed to start cease-fire negotiations. Less than half an hour before his deadline, Pastrana accepted the eleventh-hour accord and called off his troops.

The latest violence seemed to take officials and average Colombians by surprise. There was no immediate comment from the rebels on the purpose or timing attacks, but throughout the three-year period of talks, FARC had continued to launch attacks and take hostages for ransom.

Bell said that because of the attacks, troops would maintain their positions around the rebel zone.

The bombing and prison breakout will leave rebel negotiators with the daunting task of convincing Colombians they are serious about ending 38 years of a civil war that kills some 3,500 people each year.

U.N. envoy James LeMoyne said the peace process is in a "difficult moment."

"Both sides should avoid provocative military actions," he urged Tuesday.

Pastrana had been criticized for his decision three years ago to cede the Switzerland-sized safe haven to the FARC to lure them to the negotiating table. When the talks — which have yielded virtually nothing — collapsed last week, he prepared the military to take back the region.

When peace talks resume Wednesday in the southern safe haven, negotiators will have just five days to show progress on a cease-fire agreement. On Sunday, Pastrana must decide whether to extend the safe zone — as he has done repeatedly — or whether to send in troops to retake it as he threatened to do this week.

"With today's declaration, Colombians are not going to recover their faith in the FARC's word or their desire for peace," Pastrana said in a televised address to the nation Monday night.

The FARC has been accused of using the zone to produce drugs, hide kidnap victims, and prepare attacks on neighboring towns.

The war is being closely watched in Washington. The United States has given Colombia millions of dollars in military aid to combat the drug industry, which is protected and taxed by the guerrillas and the paramilitaries.

John Walters, the White House's new drug czar, was expected to arrive in Colombia on Tuesday for a three-day trip that will include meetings with Pastrana and Gen. Fernando Tapias, commander of the armed forces.

In Puente Quetame, some 30 miles south of the capital, Bogota, attacks by FARC fighters damaged a police station and a nearby courthouse, an army lieutenant said as he led 80 soldiers into town.

"While the president was talking about a cease fire, here we were in battle," said resident Marina Suarez as soldiers fired machine guns into the mountains above her home.

In the nearby town of Ibague, FARC rebels blasted into a prison and freed 39 suspected rebel members, authorities said. One guard was killed, according to Victor Paez, director of the national prison system.

And in the towns of Guayabal and Cubarral, rebels used dynamite to destroy two electrical pylons, causing rolling black-outs throughout Meta province in the south, authorities said.

Rebels also attacked the town of Algeciras, 175 miles southwest of Bogota, leveling the police station late Monday night. Army troops were sent in to repel the attack. At least three FARC rebels were killed, army officials said.