BOGOTA, Colombia (AP) _ Dynamite hidden in a lamppost exploded as the defense minister was leaving his office, killing three bodyguards and wounding two but leaving the minister unhurt, authorities said.

Callers saying they were urban communist rebels claimed responsibility for Tuesday night's attempt to kill Gen. Manuel Jaime Guerrero Paz, who was appointed defense minister just two weeks ago.

Surrounded by bodyguards, Guerrero Paz was leaving the Defense Ministry at 8:15 p.m. EST when the 20-pound charge was detonated by remote control, police said. The blast destroyed a Toyota van and sent three bodyguards and their motorcycles into the air, they said.

The armor-plated Lancia automobile in which Guerrero Paz was riding was not damaged, and its driver immediately drove it into the building's courtyard, the ministry's press office said.

The explosion opened a hole in the pavement and blew out windows of homes across the street from the Defense Ministry.

Three enlisted men who were guarding the minister were killed, and two others were hurt but out of danger in a police hospital, the press office said.

People claiming to represent an arm of the communist Revolutionary Armed Forces of Colombia guerrilla group called radio stations and claimed responsibility for the assassination attempt.

Guerrero Paz was named defense minister after President Virgilio Barco forced the resignation of his predecessor, Gen. Rafael Zamudio Molina, for ordering all-out war against leftist guerrillas.

The rebels have launched a recent campaign of terrorist attacks and sabotage that political analysts say have thrown the country into chaos.

Guerrero Paz promised last week to maintain the course advocated by Barco, who seeks a negotiated political solution with leftist guerrillas.