At least 34 people died when a landslide buried a bus in northwestern Colombia on Sunday, the government disaster agency was quoted by Reuters as saying.

The landslide, caused by heavy rain, hit the bus on the road about 230 km northwest of the capital Bogota, the national agency for managing risks and disasters (UNGRD) said in a statement.

Rescuers are digging through the mud for survivors and authorities said nine people have been rescued alive. Eight of the victims were minors, the UNGRD said.

Colombia has been affected by an unusually heavy rainy season, blamed on the La Nina weather phenomenon.