A car packed with explosives has blown up in an office district of Colombia's capital Bogota, shattering windows in dozens of buildings and injuring nine people, police said.
No deaths were reported but officers said the car contained at least 110 pounds (50 kilograms) of explosives.
It was the first car bombing in Bogota since a blast killed two people a year and a half ago and came five days after Juan Manuel Santos was sworn in as president.
The blast occurred at 5:30 am outside a 12-story building housing Caracol Radio, the Spanish news agency EFE and the Ecuadorean consulate, as well as the offices of several banks and politicians, including former President Cesar Gaviria.
Hermes Ardila, chief of prosecutors in a special anti-terrorism unit., said investigators had not linked the attack to any particular armed group.
The president hurried to the scene and called 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 replaced 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 security agents and urged Colombians to go on with normal activities.
Bogota's health secretary, Hector Zambrano, said at least nine people were injured. Most were treated for cuts and released from hospital, but three people remained under care, he said.