Bogota's police chief, Gen. Luis Eduardo Martinez, blamed the country's main leftist rebel group, the Revolutionary Armed Forces of Colombia, or FARC, though without offering any evidence.

But President Juan Manuel Santos said immediately afterward that it was too early to assign blame, and he announced a $277,000 reward for information leading to those responsible.

"We don't know who is behind this attack," he said after meeting with police and military brass, Bogota's mayor and the chief prosecutor. He said, however, that the FARC was behind a car bomb that was detected and deactivated elsewhere in the capital earlier Tuesday.

Santos, who as defense minister in 2006-2009 dealt major setbacks to the rebels, vowed in response to the attack to "eliminate terrorism from the face of the earth."

Santos said Londono, 68, had in the past received death threats and had a sophisticated protection scheme involving about 19 bodyguards.