A beloved Colombian satirist, known for his irreverent parodies of political figures, was shot to death this morning while driving to work.

Two gunmen on motorcycles shot Jaime Garzon, 40, several times in the head and chest while he was sitting in his Jeep Cherokee at a traffic light several blocks from the offices of Radionet, where he had a morning show. A witness told the station that one of the gunmen jumped off his motorcycle behind the vehicle and fired five shots, leaving Garzon slumped over the steering wheel.

In addition to his political satire, Garzon had acted as an intermediary between kidnappers and the relatives of their hostages.

Although no one had claimed responsibility for the slaying by late today, law enforcement authorities said the assassination was likely the work of right-wing paramilitary death squads. Paramilitary leader Carlos Castano, who has been waging war against Marxist insurgents and suspected rebel sympathizers as part of an civil war that has claimed at least 35,000 lives in nearly four decades, denied the charge.

Garzon's killing, the highest profile murder in Colombia since the 1995 slaying of Conservative Party leader Alvaro Gomez, prompted a national outpouring of grief. Throughout much of the day, taps was played over Radionet's airwaves behind tributes to the fallen comedian, magazine columnist and political activist, many of them by callers who were weeping.

Messages of sorrow from children were read during the programming, which was punctuated by the somber refrain, "They killed the smile." Television stations broadcast some of his old skits.

The widespread ire over Garzon's slaying underscored the growing outrage among Colombians about violence directed at the civilian population.

President Andres Pastrana, a friend of Garzon dating back to the days when both were broadcasters, announced a reward for information leading to the capture of his killers. "This is very lamentable," Pastrana told Radionet. "A friend and a colleague has been killed. This is contemptible from all points of view, and once again I want to reiterate that Colombians are tired of this type of violence, and we must look for reconciliation."

In response to the network's incantation of "They killed the smile," Pastrana added: "It was not just the laugh, because he was much more than that. . . . Jaime in large part identified with the feelings of Colombians, with what we were thinking."

Pastrana had recently named Garzon, a former mayor in a town south of Bogota, to a team of influential civilians in an effort to start peace talks with Colombia's second-largest guerrilla group, the National Liberation Army (ELN).

He was said to have close contacts with the group and had on occasion served as an intermediary between guerrillas and the families of kidnap victims, although he insisted that he did not take cuts of the ransoms paid.

In an apparent effort to force the government into talks, the ELN hijacked a small commercial airliner and abducted the 54 passengers and crew members in April. It also seized more than 130 worshipers from a church in Cali in late May. The group is still holding more than 50 of those hostages.

Garzon had also offered work for the release of police officers held by rebels. "It could be he was murdered for his humanitarian efforts," the national police commander, Gen. Rosso Jose Serrano, said today.

Scattered demonstrations were reported around the city, and a large crowd gathered tonight in Bogota's main plaza near the capitol, where Garzon's body was to be placed.

"What little laughter we had is gone. All his wonderful characters that made us forget about how bad things have been are gone with him," said Anita del Sol, 44, a beautician. "But I will never forget Jaime and the pleasure he gave us. He will live on."

Special correspondent Kirk Semple contributed to this report.