The strongest typhoon to hit the Philippines this year uprooted trees, toppled power lines and flooded villages as it barrelled across the archipelago Friday, leaving at least 12 people dead.

More than 300,000 people fled their homes and beachfront resorts as Typhoon Rai pummelled the southern and central regions of the country, knocking out communications in some areas and tearing roofs off buildings.

"As of now the monitored or initial casualties number is about 12 in total from all those regions affected," said Ricardo Jalad, executive director of the National Disaster Risk Reduction and Management Council.

Rai was a super typhoon when it slammed into Siargao Island yesterday, packing maximum sustained winds of 195km/h.

Wind speeds have eased to 155km/h, the state weather forecaster said.

"We are seeing people walking in the streets, many of them shell-shocked," ABS-CBN correspondent Dennis Datu reported from the hard-hit city of Surigao on the southern island of Mindanao.

"All buildings sustained heavy damage, including the provincial disaster office. It looks like it's been hit by a bomb."

Mr Datu said the main roads leading into the coastal city had been cut off by landslides, fallen trees and toppled power poles.

The national disaster agency said one person had been reported killed and two others injured in the storm, which was heading towards the popular tourist destination of Palawan island.

Residents salvage belongings from their destroyed homes
in the coastal town of Dulag in Leyte province

More than 300,000 people had sought emergency shelter as the typhoon charged across the Pacific Ocean and smashed into the country, the agency said.

About 18,000 had yet to return home.

Surigao City Mayor Ernesto Matugas told ABS-CBN that Rai ravaged the city of around 170,000 people for several hours, causing "severe" damage.

"The wind was very strong," Matugas said.

"Everything sustained damage - roofs blown off, access roads blocked by landslides."

Officials from the national disaster agency said it was too early to determine the extent of the damage across the country, but initial reports suggested it was "not that massive" and they were not expecting "many casualties".

"The damage was not as big as compared to previous typhoons of the same strength," Casiano Monilla, the deputy administrator for operations, told a briefing.

"Most of the damage was to infrastructure and houses," he said, adding the mass evacuation of people from their homes ahead of the storm had saved lives.

Scores of flights were cancelled across the country and dozens of ports temporarily closed as the weather bureau warned several-metre-high storm surges could cause "life-threatening flooding" in low-lying coastal areas.

"The devastation is hard to explain," said Joel Darunday, 37, a tour operator in the central island province of Bohol, who was hunkered down at home with his family when the storm ripped off the roof.

"It was very strong. The last time I experienced something like this was back in the 1980s."

Residents walk past an uprooted tree in Naga town in Cebu province

Clean-up begins

People began clearing fallen trees, branches and debris from roads as clean-up efforts and relief operations got under way in areas hit by Rai.

Verified photos taken in nearby Lapu-Lapu city showed roadside buildings flattened by the storm, while sheets of corrugated iron roofing and branches littered streets.

Some wooden houses in the coastal town of Dulag in Leyte province were destroyed, while uprooted coconut trees lay on the beach.

"We were afraid," said Ced Golingay, 31, a hotel receptionist in the central city of Iloilo who lives with her parents.

"Even in my sleep I could feel the wind lashing the house."

Communications were still down in Siargao which took the brunt of the storm.

Rai, locally named Odette, is hitting the Philippines late in the typhoon season, with most cyclones developing between July and October.

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.

Rai was moving across the Visayas region towards Palawan today and was expected to emerge tomorrow over the South China Sea, heading towards Vietnam.

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.

The deadliest cyclone on record in the Philippines was Super Typhoon Haiyan, which left more than 7,300 people dead or missing in 2013.