At least 20 people were killed and dozens injured in a bus bombing in southwestern Colombia, officials confirmed.

The attack occurred on the Pan-American Highway in Cajibio, with victims including 15 women and five men.

Regional governor Octavio Guzmán said 36 people were injured, including minors, some in critical condition.

Authorities blamed dissident groups linked to the former Revolutionary Armed Forces of Colombia, calling the incident a terrorist act, the AP has reported.

The attack is part of a surge in violence in the region, prompting mourning and international condemnation.