The strongest typhoon this year slammed into the Philippines on Friday, setting off landslides, knocking out power in several province and cutting communications in the country's central region of island provinces. Four people died.

Telephone lines appeared down as it was difficult to get through to the landfall site 650 kilometres southeast of Manila where Typhoon Haiyan slammed into the southern tip of Samar island before barrelling on to Leyte Island.

Two people were electrocuted in storm-related accidents, one person was killed by a fallen tree and another was struck by lightning, official reports said.

Nearly 720,000 people evacuated

Close to 720,000 people had been evacuated from towns and villages in the typhoon's path across the central Philippines, the National Disaster Risk Reduction and Management Council said. Among them were thousands of residents of Bohol who had been camped in tents and other makeshift shelters after a magnitude 7.2 earthquake hit the island province last month.

Philippine President Benigno Aquino III speaks in a nationally televised address at the Malacanang palace in Manila, Philippines on Thursday. Thousands of people were removed from villages in the central Philippines before the typhoon struck. (The Associated Press) Southern Leyte Gov. Roger Mercado said 31,000 people were evacuated in his landslide-prone mountainous province before the super typhoon struck, knocking out power, setting off small landslides that blocked roads in rural areas, uprooting trees and ripping roofs off houses around his residence.

The dense clouds and heavy rains made the day seem almost as dark as night, he said.

"When you're faced with such a scenario, you can only pray, and pray and pray," Mercado told The Associated Press by telephone, adding that his town mayors have not called in to report any major damage.

"I hope that means they were spared and not the other way around," he said. "My worst fear is there will be many massive loss of lives and property."

Television images from Tacloban city on Leyte Island showed a street under knee-deep floodwater carrying debris that had been blown down by the fierce winds. Tin roofing sheets ripped from buildings were flying above the street.

Visibility was so poor that only the silhouette of a local reporter could be seen through the driving rain.

'Catastrophic damage' feared

Weather officials said that Haiyan had sustained winds at 235 kilometres per hour, with gusts of 275 km/h when it made landfall. That makes it the strongest typhoon this year, said Aldczar Aurelio of the government's weather bureau.

Gener Quitlong, another weather forecaster, said the typhoon was not losing much of its strength because there is no large land mass to slow it down since the region is comprised of islands with no tall mountains.

The typhoon — the 24th serious storm to hit the Philippines this year — is forecast to blow toward the South China Sea on Saturday, heading toward Vietnam.

Filipino workers bring down a giant billboard along a busy highway as they prepare for the possible effects of powerful Typhoon Haiyan in suburban Makati, south of Manila, Philippines, on Thursday. (The Associated Press) Jeff Masters, a former hurricane meteorologist who is meteorology director at the private firm Weather Underground, said the storm had been poised to be the strongest tropical cyclone ever recorded at landfall. He warned of "catastrophic damage."

But he said the Philippines might get a small break because the storm is so fast moving that flooding from heavy rains — usually the cause of most deaths from typhoons in the Philippines — may not be as bad.

As it approached the Philippines, the storm was one of the strongest on record.

The U.S. Navy's Joint Typhoon Warning Center said shortly before the typhoon made landfall that its maximum sustained winds were 314 km/h, with gusts up to 379 km/h. Those measurements are different than local weather data because the U.S. Navy centre measures the average wind speed for 1 minute while local forecasters measure average for 10 minutes.

Hurricane Camille, a 1969 storm, had wind speeds that reached 305 km/h at landfall in the United States, Masters said.

Officials in Cebu province have shut down electric service to the northern part of the province to avoid electrocutions in case power pylons are toppled, said assistant regional civil defence chief Flor Gaviola.

President Benigno Aquino III assured the public of war-like preparations, with three C-130 air force cargo planes and 32 military helicopters and planes on standby, along with 20 navy ships.