Thousands of people in the northern Philippines are seeking shelter as a powerful typhoon lashes the area with heavy rain, strong winds and surging waves.

Typhoon Megi, which some forecasters have called a "super typhoon," had sustained winds of 225 km/h and gusts of 260 km/h as it made landfall at Palanan Bay in northeastern Isabela province, The Associated Press reported.

"Thousand of homes were evacuated and even though the storm is weakening, it will continue to bring flooding rains and mudslides as it tracks west across land," said CBC meteorologist Johanna Wagstaffe.

At least three people were killed and six were injured as a result of the typhoon, local officials said.

Although initial casualties were low compared to past storm disasters, retired army Maj.-Gen. Benito Ramos, who heads the country's disaster-preparedness agency, expressed sadness over the deaths. Bracing for the typhoon, he said, was like "preparing for war."

Many coastal areas were evacuated before the typhoon made landfall, but emergency teams and relief organizations were still concerned about public safety.

"If you have a landslide, and people have not evacuated on the ground, it can cost thousands of lives," said Richard Gordon, chairman of the Philippines Red Cross.

"That's why we are focusing the whole operation of the government and the Red Cross and other agencies — including local governments and the military — are all focused on trying to make sure minimal lives are lost in this typhoon," he said.

The storm tore through homes, uprooted trees and blew down power lines, cutting off power in Isabela province and large swaths of Cagayan province.

Cagayan Governor Alvaro Antonio said the wind was fierce but blew high from the ground, sparing many rice fields ready for harvesting.

In some areas, emergency crews were relying on two-way radios to communicate because the storm had knocked out phone and internet service, Manila-based freelance reporter Dean Bernardo said.

Ships and fishing vessels were told to stay in port, and several domestic flights also were cancelled.

Weather forecasts said the capital is expected to be spared a direct hit this time, although the lowest weather alert was in effect Monday with preschools closed.

Megi is the most powerful typhoon to hit the Philippines in four years, government forecasters said. A 2006 howler with 250 km/h winds set off mudslides that buried entire villages, killing about 1,000 people.

Floods deadly in Vietnam

The storm is expected to move toward China, where authorities evacuated 100,000 people from a coastal province. It could also pass by Vietnam, where at least 30 people have died as a result of heavy flooding unrelated to the typhoon.

A woman guides her small boat past a flooded home in central Quang Binh province, Vietnam, on Sunday. (Ho Cau/Vietnam News Agency/Associated Press)

On Monday, strong currents on Vietnam's flooded main highway swept away a bus and 20 of its passengers, including a boy pulled from his mother's grasp.

"People are exhausted," Vietnamese disaster official Nguyen Ngoc Giai said by telephone from Quang Binh province.

"Many people have not even returned to their flooded homes from previous flooding, while many others who returned home several days ago were forced to be evacuated again."

The typhoon was expected to enter the South China Sea on Tuesday, China's National Meteorological Centre said.

The centre issued its second-highest alert for potential "wild winds and huge waves," warning vessels to take shelter and urging authorities to brace for emergencies.

Floods triggered by heavy rains forced nearly 140,000 people to evacuate from homes in the southern island province of Hainan, where rains left thousands homeless over the weekend, the official Xinhua News Agency reported Monday.

Thailand also reported flooding that paralyzed parts of the country, submerging thousands of homes and vehicles and halting train service. No casualties were reported, but nearly 100 elephants were evacuated from a popular tourist attraction north of the capital.

With files from The Associated Press