A bomb exploded in front of a beauty salon in Colombia's capital Thursday night as a police car drove by, killing two officers and wounding two other people, authorities said.
National Police chief Gen. Jorge Daniel Castro said they had no suspects in the blast, which blew out windows and caused panic in the residential neighborhood in northwest Bogota.
Another police officer in the patrol car was injured in the blast, as was a woman walking nearby.
Residents in the area said they heard another explosion a few minutes after the first bomb, but no further details were available.
Castro offered $40,000 for information leading to the arrest of those responsible.
Colombia is involved in a four-decade rebel conflict that pits the government against Marxist rebel groups and right-wing paramilitary fighters labeled terrorist organizations by the United States.