No group had claimed responsibility for the blasts near Colombia's National University, and officials said they were unaware of a motive. Colombia is rife with violent drug traffickers and criminal gangs, and is immersed in a 37-year armed conflict involving guerrillas, paramilitary militias and the security forces.
Bogota's police chief, Gen. Jorge Enrique Linares, said the bombs were placed on both sides of the divided highway by four men wearing ski masks who had arrived in a black truck. One exploded prematurely, killing one of the bombers, Linares said.
The second explosion took place after police, firefighters, and agents from the federal prosecutor's office had arrived at the scene. One of the agents was killed, and two police wounded in the second blast, Linares added. He said there were 21 people wounded in all.
Live images captured by RCN television showed the second bomb going off near a pedestrian overpass, shooting debris into the sky and sending up a plume of dark smoke from a grassy median where rescue workers had gathered.
One firefighter collapsed. A colleague gently removed his yellow helmet and loosened his clothing as scores of terrified pedestrians ran from the area. TV reports said one of those killed in the second blast was a policeman.
Corpses covered in white blankets were laid out on the street, which was littered with shards of glass, papers and clothes.
Bomb squads successfully deactivated a third bomb in the same area, a middle class residential Bogota neighborhood.
The explosions came days after a large bomb was disarmed in Bogota in front of a communist newspaper and eight days after a car-bomb exploded in the second city of Medellin, killing eight people and wounding 138.
Another car bomb exploded in a hotel parking lot in Cali, the third-largest city, wounding dozens of people, including members of a Colombian soccer team.
The attempted bombing in Bogota was widely blamed on right-wing paramilitaries and two blasts in Medellin have been linked to an urban mafia led by drug lord Pablo Escobar's former hit men, known as La Terraza. Police blame the Medellin attacks on a turf war between La Terraza and the paramilitaries.
The explosions have stoked fears of a terrorism wave in Colombia, similar to one waged in the 1980s and early 1990s by the Medellin cartel in its attempt to pressure the government into barring the extradition of drug traffickers to the United States.
On Thursday, Bogota's police force said it was erecting 100 roadblocks and devoting 2,000 officers to prevent terrorist attacks in the capital.
The recent explosions have undermined confidence that Colombia will be able to safely stage the Americas Cup soccer championship iJuly.
Friday's explosions were just 500 yards from El Campin stadium, where some of the matches will be played.
Police cordoned off a 200-yard area of the middle class neighborhood an hour after the explosions as rumors spread there were more bombs in the city. Residents peered out from shattered windows of apartment buildings overlooking the site.
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