The death toll from a typhoon that ravaged the Philippines jumped to 274 Wednesday with hundreds more missing, as rescuers battled to reach areas cut off by floods and mudslides.

Typhoon Bopha slammed into the southern island of Mindanao Tuesday, toppling trees and blowing away thousands of homes with 210-kilometre (130-mile) per hour gusts before easing and heading towards the South China Sea.

A total of 253 people died in and around the gold-rush mountain towns of New Bataan and Monkayo due to typhoon-spawned landslides and flash floods there, civil defence chief Benito Ramos told reporters.

Twenty-one people were killed in other parts of the southern island of Mindanao and the central islands, he added.

Cabinet members Mar Roxas and Corazon Soliman, who flew to the south to inspect the damage, described scenes of utter devastation with thousands of houses ripped apart and corpses lying on the ground.

"These are whole families, six or seven names with the same surnames. It is saddening to think entire families have been washed away," Interior Secretary Roxas said.

"There is hardly any structure that is undamaged," he said in an interview over ABS-CBN television.

"We need to rush to these areas body bags, medicines, dry clothes and most importantly tents, because survivors are living out in the open," Social Welfare Secretary Soliman told AFP.

Bodies caked in mud were being transported on the back of army trucks and laid out in rows on tarpaulins where relatives searching for missing family members broke down as they identified the shrouded corpses of loved ones.

Shell-shocked survivors scrabbled through the rubble of their homes to find anything that could be recovered among a surrounding wasteland of flattened banana and coconut trees.

Ramos said 279 other people were still missing, while 339 others were treated for injuries.

About 178,000 people remained huddled in evacuation centres, mostly crowded schoolhouses, gyms and other government buildings, officials said.

Meanwhile, rescue personnel still struggled to reach areas cut off by the storm where many more casualties might be found.

President Benigno Aquino said he hoped the country was learning from its frequent natural disasters, including the roughly 20 cyclones that hit each year.

"Any single casualty is a cause for distress. Our aim must always be about finding ways to lessen them," he told reporters in Manila, while pointing out the "big difference" in casualty counts compared with previous storms.

The more than 500 dead or missing in Bopha was still below the 1,200 deaths from tropical storm Washi, which hit in December 2011, leaving hundreds of thousands homeless in Mindanao, he said.

The United Nations office for disaster risk reduction said many lives had been saved by improved early warning systems.

Jerry Velazquez, who heads the agency's Asia office, singled out new automated rainfall and flood predictions systems, which he said had greatly improved forecasting and made it possible to more quickly alert people at risk.

He said they have "enabled central government agencies, local governments and citizens to prepare and act before intense weather arrives".

President Aquino said the government was also investigating why an army patrol base in New Bataan, which was washed away in the flash floods, had been located in a flood-prone area.

Officials were also checking reports that an evacuation centre there was among the structures wiped out in the floods, the president added.

"According to (survivors), there is a small lake on the mountain that gave way so the waters flowed down, not just along the rivers... but all across, like a waterfall, bringing a slurry that covered the whole town," Roxas said.

One shelter there had caved in during the typhoon, forcing the people inside to flee to an even smaller building, he said.

Bopha was the most powerful of the 16 storms to pummel the Philippines this year, though Mindanao is not usually on the front line.

Regional military spokesman Lieutenant Colonel Paniza said three soldiers taking part in rescue operations were killed in New Bataan, with eight others from the same unit among the missing.

"It is quite sad and tragic. They were actually there to be ready to help our countrymen who may be in trouble," Roxas said.