Comes after $108m Typhoon Ketsana and heavy flooding

Typhoon Parma, 180 km (110 miles) northeast of the island of Catanduanes in the central Philippines, has been gaining strength as it tracks west-northwest toward the Luzon mainland, bringing heavy rain. The Philippines has declared a nationwide state of calamity. Flash floods have recently killed nearly 300 people in and around Manila.

Parma is expected to make landfall near the northeastern province of Isabela on Saturday. The area is mountainous and not heavily populated, but Parma is likely to cause heavy rain in Luzon, making life worse in flood-hit regions.

"We're concerned about the effects of more rain on the relief work in flooded areas because the water level could rise again," Defence Secretary Gilberto Teodoro said in a briefing aired live on national television.

The Asia-Pacific region has been hit by a series of natural disasters in recent days, including Typhoon Ketsana which killed more than 400 in the Philippines, Vietnam and Cambodia.

Two powerful earthquakes rocked the Indonesian island of Sumatra, with the death toll likely to be in the thousands, and a tsunami battered American and Western Samoa, killing nearly 150.

In Taiwan, authorities identified 12 villages for mandatory evacuation ahead of Parma and another storm in the Pacific, Typhoon Melor.

The Taiwan government came in for heavy criticism after a deadly typhoon in August killed as many as 770 people.

In the Philippines, harsh criticism of the slow response to last week's floods could affect the chances of Teodoro at next May's presidential election, where he is seeking to replace President Gloria Macapagal Arroyo.

Teodoro, who is also the head of the National Disaster Coordinating Council, has placed the military and police on alert and ordered civilian agencies to stockpile food, water, medicine, fuel and other relief supplies.

Arroyo declared a state of calamity across the country, which will allow local governments access to emergency funds for relief work.

She also ordered provincial governments to evacuate people living in low-lying areas in the path of Parma, by force if necessary.

The weather bureau said Parma, with gusts of up to 230 kph (143 mph) at the center, will be the strongest typhoon to hit the country since 2006.

"It's still very much possible that we will raise signal number 4 as it closes in on northern Luzon," Prisco Nilo, head of the weather bureau, told reporters.

At signal number 4, residential and commercial buildings may be severely damaged, large trees uprooted, and power and communication lines may be cut.

Last week's storm, Ketsana, left tens of thousands homeless in and around Manila and areas around a lake near the capital remain submerged under 2-3 meter floodwaters. It also damaged or destroyed more than $108 million in crops, infrastructure and property.