Aerial photos show destruction due to Typhoon Rai in Philippines

The Philippines -- ranked as one of the world's most vulnerable countries to the impacts of climate change -- is hit by an average of 20 storms and typhoons every year.

More than 30 people were killed in the strongest typhoon to hit the Philippines this year, official figures showed Saturday, with a charity reporting "alarming" destruction on islands that bore the brunt of the storm.

Hundreds of thousands fled their homes and beachfront resorts as Typhoon Rai ravaged the southern and central regions of the archipelago, knocking out communications and electricity in many areas, ripping off roofs and toppling concrete power poles.

Typhoon Rai was a super typhoon when it smashed into the popular tourist island of Siargao on Thursday, packing maximum sustained winds of 195 kilometres per hour (120 miles per hour).

Aerial photos shared by the military showed widespread damage in the town of General Luna, where many surfers and holidaymakers had flocked ahead of Christmas, with buildings stripped of roofs and debris littering the ground.

"Everything was flying, it was as if it was the end of the world," Raphy Repdos, a tour operator visiting the island when the storm hit, told AFP.

"The wind sounded angry and roaring, as if it wanted to demolish the building."

The neighbouring island of Dinagat had been "levelled to the ground" by the storm, Governor Arlene Bag-ao wrote on Facebook, saying houses, boats and fields were destroyed.

Rai's wind speeds eased to 150 kph as it barrelled across the country, dumping torrential rain that flooded villages, uprooting trees and shattering wooden structures.

It emerged over the South China Sea on Saturday and was headed towards Vietnam, the state weather forecaster said.

"This is indeed one of the most powerful storms that has hit the Philippines in the month of December in the last decade," Alberto Bocanegra, head of the International Federation of Red Cross and Red Crescent Societies in the Philippines, told AFP.

"The information we are receiving and the pictures we are receiving are very alarming."

At least 33 people have been reported killed in the storm, according to official tallies. 

A disaster official in the central province of Negros Occidental told AFP 13 people had died, most by drowning, and that another 50 were missing in a flood-hit area.

"We started urging people to evacuate as early as Wednesday but many were reluctant to leave," Salvador Mesa said.

More than 18,000 military, police, coast guard and fire personnel will join search and rescue efforts in the worst-affected regions, Mark Timbal, spokesman for the national disaster agency, told AFP.

The Philippine Coast Guard has shared photos on social media showing widespread destruction around Surigao City on Mindanao.

Shattered glass from smashed windows, sheets of corrugated iron roofing, power lines and other debris were scattered in the streets. 

The vice governor of Dinagat said residents on the island of around 128,000 people were "trying to repair their houses because even our evacuation centres were torn down." 

"They can't seek refuge anywhere else... everything was destroyed," Nilo Demerey told ABS-CBN.

Scientists have long warned that typhoons are becoming more powerful and strengthening more rapidly as the world becomes warmer because of human-driven climate change.

The Philippines -- ranked as one of the world's most vulnerable countries to the impacts of climate change -- is hit by an average of 20 storms and typhoons every year, which typically wipe out harvests, homes and infrastructure in already impoverished areas.