The truck carrying explosives exploded near a police station. Eight police officers and three civilians were injured.
The US-backed right-wing politician Abelardo de la Espriella succeeds outgoing left-wing President Gustavo Petro.
Abelardo de la Espriella is sworn in as president on August 8.
The presidential election in Colombia was marked by violence, with an escalation of the armed conflict and attacks on the country's security forces.
