A car packed with at least 110 pounds (50 kilograms) of explosives blew up in an office district of Colombia's capital on Thursday, shattering windows and injuring at least nine people, police said. No deaths were reported.

The blast occurred at 5:30 a.m. (1030 GMT) outside a 12-story building housing Caracol Radio, the Spanish news agency EFE and the Ecuadorean consulate, as well as the offices of several politicians and banks.

Gen. Cesar Pinzon, the city's police chief, suggested leftist rebels could have set off the blast, but said authorities were not sure if the bomb was aimed at the station or another target.

President Juan Manuel Santos hurried to the scene and branded the explosion "a terrorist act," saying it was meant to sow fear and create skepticism about the government.

"We are going to continue fighting terrorism with everything we have," said Santos, who took office on Saturday. He replaces Alvaro Uribe, whose tough tactics sharply weakened the leftist guerrilla groups that have fought the government for decades.

Santos toured the blast site surrounded by a cloud of security agents and urged Colombians to go on with normal activities.

The director of technical investigations for the prosecutor's office, Marilu Mendez, said it was too early to determine the intended target of the attack. She said no arrests had been made.

Bogota's health secretary, Hector Zambrano, said at least nine people were injured. Most were treated for cuts and released, but three people remained under care, he said.

Pinzon said most of those hurt had been on a bus that was passing by as the bomb exploded.

The national police operations director, Gen. Orlando Paez, said the car was packed with at least 110 pounds (50 kilograms) of explosives and the blast shattered windows in at least 30 buildings, smashed the facade of a bank and left scraps of the destroyed car scattered in the street.

Pinzon said authorities had located the owner of the car that exploded, and said it had been reported stolen on July 30 from a shopping center in the north of the city.

Caracol Radio continued broadcasting despite the blast. EFE said its offices were not damaged and officials at the Ecuadorean consulate said police had not yet allowed them into their offices to see what had happened there.

A car bomb that exploded in March in the Pacific coast city of Buenaventura killed at least nine people and injured about 50. Bogota had not suffered a car bombing since January 2009, when a blast at an automatic teller machine killed two people.

Source: Associated Press