Typhoon Usagi slammed into thePhilippines' already disaster-ravaged north on Thursday, as authorities rushed to evacuate thousands of people from flood-prone areas.

The fifth storm to strike the country in just three weeks, Usagi made landfall in the town of Baggao in Cagayan province at 0530 GMT, packing winds of 175 kilometers (109 miles) an hour, the national weather service said.

The brutal wave of weather disasters has already killed 159 people and prompted the United Nations to request $32.9 million in aid for the worst-affected regions.

The national weather agency had initially raised its highest storm alert, but downgraded to its second-highest as Usagi made landfall.

It weakened to 165 kilometers an hour as it ploughed north to the municipality of Gonzaga and open waters beyond it.

Baggao police said no casualties or substantial damage were immediately reported, while 28 residents of a village were evacuated amid concern it would get flooded.

"It was weaker than we expected," a relieved police officer, Karen Ibarra, told AFP by phone.

President Ferdinand Marcos, visiting storm-affected areas to dole out emergency cash aid, urged residents to comply with evacuation orders.

"We know that it is difficult to leave your homes and possessions, but sheltering could save lives," he told residents of Mindoro island south of the capital Manila, according to an official transcript of his speech.

"While we cannot prevent typhoons from hitting the country, we can take steps to reduce their impact," he said, calling for better infrastructure to cope with worsening storm effects he blamed on climate change.

'Forced evacuations'

Elsewhere in Cagayan, officials worked in driving rain Thursday to evacuate residents along the coasts and on the banks of already swollen rivers.

"Yesterday it was preemptive evacuations. Now we're doing forced evacuations," local disaster official Edward Gaspar told AFP by phone hours before landfall, adding 1,404 residents were sheltering at a municipal gym in Gonzaga.

Cagayan's civil defence chief Rueli Rapsing said he expected local governments to take 40,000 people to shelters, roughly the same number that were removed from their homes ahead of Typhoon Yinxing earlier this month.

He said more than 5,000 Cagayan residents were still in shelters following the previous storms because the Cagayan river, the country's largest, remained swollen from heavy rain that fell in several provinces upstream.

Overlapping typhoons

After Usagi, Severe Tropical Storm Man-yi is forecast to strike the densely-populated capital Manila on Sunday.

This was similar to the path of last month's Severe Tropical Storm Trami, which accounted for most of the deaths tallied in the recent swarm of weather disasters to hit the country.

Local officials were ordered to convince residents of flood- and landslide-prone communities in Man-yi's path to move to shelters on Friday ahead of its landfall, the civil defence office said.

"Typhoons are overlapping. As soon as communities attempt to recover from the shock, the next tropical storm is already hitting them again," said Gustavo Gonzalez, the UN's humanitarian coordinator in the Philippines.

"In this context, the response capacity gets exhausted and budgets depleted."

A UN assessment of the past month's weather disasters said 207,000 houses had been damaged or destroyed, and nearly 700,000 people were seeking temporary shelter.

Many families were without even essentials like sleeping mats, hygiene kits, and cooking supplies, and had limited access to safe drinking water, it said.

The storms destroyed thousands of hectares of farmland and persistent flooding is likely to delay replanting efforts and worsen food supply problems, the report added.

About 20 big storms and typhoons hit the archipelago nation or its surrounding waters each year, killing scores of people and keeping millions in enduring poverty.

A recent study showed that storms in the Asia-Pacific region are increasingly forming closer to coastlines, intensifying more rapidly and lasting longer over land due to climate change.