A car bomb has exploded at an airport in the Colombian city of Medellin, injuring at least nine people.

The explosion happened outside offices in the airport's cargo area, damaging nearby buildings and vehicles.

No one has claimed responsibility for the attack.

It's the second bombing in Colombia in less than a week.

Last Friday, eight small bombs exploded outside banks in Bogota.

The National Liberation Army, the country's second biggest rebel group, later said it had planted the explosives.