Manila, Philippines: A truck carrying hog feed smashed into the rear of a passenger bus on a remote downhill provincial road in the northern Philippines early Saturday, setting off a series of wrecks that left at least 20 people dead and injured 44 others, police said.

The bus driver lost control of his vehicle after the first collision and hit two buses and four vans coming from the opposite direction before toppling over on the narrow downhill road in Quezon province on Luzon island, about 115 kilometers (72 miles) southeast of Manila, Atimonan town police chief Jonar Yupio said. Parts of the bus pinned many of the victims, and others were killed by flying metal debris, including the engine.

All those killed – including four children, the truck driver and his assistant – were in either the truck or the first bus that was hit.

Social workers said a 1-year-old girl was among the survivors. Rescuer Jun Panuil said he found the baby muddied and covered in blood from other victims on the side of the road near the bus. He said the blood had made rescuers suspect the child was seriously hurt, but she had only a few scratches.

Yupio said it was dark and raining when the accident occurred early Saturday morning, shortly past midnight. He said the bus and truck involved in the first collision rolled over before stopping on their sides.

The injured, most of them passengers on the first bus that was hit, were brought to separate hospitals, Yupio said. An investigation has been launched.

Road accidents are common in remote areas in the Philippines, largely because of poor vehicle maintenance and bad road conditions.