COTABATO, Philippines (AP) _ A bus overloaded with holiday travelers plunged into a deep ravine Monday, flipping over three times down the rocky slope, killing at least 30 people and injuring dozens, police said.

The bus was speeding along a sharp hillside curve when another bus raced to overtake it, smashing it in the rear and driving it into the 60-foot-deep ravine on the island of Mindanao, said police.

At least 23 passengers died on the scene and seven more died in hospital, said police. Others, including the driver, were in critical condition in several hospitals in the area some 600 miles southeast of Manila.

Police said the bus had a passenger capacity of 60 but was overcrowded, with many passengers standing in the aisle. Police said the driver apparently sped up to avoid being overtaken on the curve and lost control of the steering wheel when the other bus hit him from behind.

The bus, traveling between the cities of Cotobato and Davao, crushed to death several of the passengers who fell out during the fall, said Reynaldo Ocampo of the Bansalan Municipal Police said. He said several seriously injured passengers were still trapped in the bus hours after the crash and others may be under the bus.

He said police were only able to recover 14 bodies in the few hours after the crash and fear that some of the seriously injured may still be trapped inside the demolished bus.

Nobody was hurt on the other bus, but police took the driver in for questioning.