Imbudo struck Palanan town on the east coast of the main island of Luzon at 10:00 am (0200 GMT) with peak sustained winds of nearly 200 kilometers per hour (nearly 120 miles an hour) before sweeping northwest across a 450-kilometer (279-mile) front, the weather bureau said.

The typhoon later weakened to about 140 kilometers (87 miles) an hour as it crossed the northern Luzon mountain ranges.

The strongest typhoon to strike the Philippines in five years uprooted trees and triggered floods that killed at least six people and left a fisherman missing at sea, officials said.

The deaths included four high school students and a tricycle driver who were crushed to death on central Romblon island when struck by a tree felled by high winds, the civil defense office said.

Social Welfare Secretary Corazon Soliman said one other victim drowned in the northern town of Alcala, while the coastguard said a fisherman went missing after a boat capsized off the western island of Palawan.

The civil defense office said nine other people were injured.

More than 2,000 families were evacuated after flash floods were reported to have washed away an estimated 50 houses in several towns in the southern province of Maguindanao, it added.

All government offices were closed by noon and officials declared a school holiday in Manila, where high winds and strong rain disrupted power supply.

Most of northern Luzon was without power or telephone services, the civil defense office said.

At least four domestic flights were cancelled while power outages disabled Manila's overhead Light Railway Transit, which serves tens of thousands of commuters daily, for two hours.

Soliman said the coastguard opened the major ferry crossing of Allen on Samar island and Matnog on southeastern Luzon in midmorning, easing the backlog of vehicles that had left up to 2,000 seafarers stranded overnight Monday.

Weather forecaster Rick Fabregas said the eye of Imbudo was about 80 kilometers (50 miles) northeast of the northern resort city of Baguio at 2:00 pm (0600 GMT), and was expected to move into the South China Sea Tuesday night.

About 300 people were killed when a similar-strength typhoon hit the Philippines in 1998, the weather bureau said.

Authorities warned residents of low-lying areas and near mountain slopes to be on alert for floods and landslides, as well as coastal flooding on Luzon's east coast. The Red Cross said uprooted trees blocked relief convoys going to the Palanan area.

TERRA.WIRE