A strong explosion rocked one of the busiest shopping centers in Colombia's capital Saturday, killing three people including a 23-year-old French woman and injuring nine, authorities said.

Witnesses told of being evacuated from movie theaters and stores after a blast in a second-floor bathroom. Ambulances and firetrucks rushed to the scene and the injured were taken to a hospital.

Bogota Mayor Enrique Penalosa condemned what he called a "cowardly terrorist bombing" at the upscale Centro Andino in the heart of Bogota's tourist district.

He said the victim had been in Colombia the past six months volunteering in a poor neighborhood and was preparing to return to France in the coming days. Of the 11 injured, three suffered serious injuries, he said.

Authorities' attention immediately focused on the country's largest still active rebel group, the National Liberation Army, or ELN, which in February claimed responsibility for a bombing near Bogota's bullring that killed one police officer and injured 20 other people.