A bomb exploded on a street in Medellin as a bus carrying policemen to night patrol duty passed by, killing five officers and injuring 15, many critically, police said.
No one claimed responsibility for the attack late Thursday, but police blamed drug barons angered by the government's refusal to negotiate its policy of extraditing traffickers to the United States."The traffickers are the only criminals with the means and the desire to carry out an attack of this size," said a police spokesman in Medellin, the center of Colombia's drug trade.
Hours later, two bombs exploded in Bogota, the capital, injuring one person.
In the two months since the government declared a war on traffickers and the drug lords responded with violent attacks, 168 bombings attributed to the traffickers have killed 21 people and injured 218.
The latest attacks came a day after the country suffered its worst rebel violence in two years, with guerrillas storming two northeastern towns and slaying at least six people, according to army reports.
The bomb in Medellin, packing over 60 pounds of dynamite, was placed on a curb and detonated as the bus passed. National RCN radio said 44 officers were on the bus at the time.
The driver and four others died in the explosion, which severely damaged the bus and sent it reeling out of control, the police spokesman said. Many of the 15 injured were in critical condition, he said.
The bus finally stopped when it smashed into a parked taxi, the spokesman said.
The vehicle was carrying police officers to their posts for night duty. The attack stirred panic in Medellin's residential neighborhood of Bello Horizonte.
"The terrorists fired automatic rifles as they fled, and people panicked because they thought the neighborhood was under attack," the spokesman said.