Another dangerous storm is barrelling towards the Philippines, threatening an area where dozens of people were killed by flash floods and landslides just weeks ago, the weather service said.

Typhoon Usagi blew out of the archipelago nation on Friday as rescuers worked to reach residents stranded on rooftops in northern Luzon island, where herds of livestock were devastated.

Thousands of people were displaced by Usagi, the fifth major storm to hit the country in less than a month.

It weakened as it headed towards Taiwan, after blowing away houses in its path.

The recent wave of disasters has killed at least 159 people and prompted the United Nations to request $32.9m in aid for the worst-affected regions.

On Thursday, flash floods caused by Usagi struck 10 largely evacuated villages around the town of Gonzaga in Cagayan province, local rescue official Edward Gaspar told the AFP news agency.

“We rescued a number of people who had refused to move to the shelters and got trapped on their rooftops,” Gaspar said.

Trees uprooted by flooding damaged a major bridge in Gonzaga, isolating nearby Santa Ana, a coastal town of about 36,000 people, Cagayan officials said.

“Most evacuees have returned home, but we held back some of them. We have to check first if their houses are still safe for habitation,” Bonifacio Espiritu, operations chief of the civil defence office in Cagayan, told AFP.

By early Friday, Usagi was over the Luzon Strait with a reduced strength of 120km/h (75mph) as it headed towards southern Taiwan, where authorities downgraded it to a tropical storm.

But the streak of violent weather was forecast to continue in the central Philippines, where Tropical Storm Man-yi is set to reach coastal waters by Sunday.

The weather service said it could potentially strike at or near the heavily populated capital, Manila.

According to a UN assessment, the past month’s storms damaged or destroyed 207,000 houses, with 700,000 people forced to seek temporary shelter.

Many families were without essentials such as sleeping mats, hygiene kits and cooking supplies, and had limited access to safe drinking water.

Thousands of hectares of farmland were destroyed and persistent flooding was likely to delay replanting efforts and worsen food supply problems, the report added.

About 20 big storms and typhoons hit the Southeast Asian nation or its surrounding waters each year, killing dozens of people and keeping millions in enduring poverty, but it is unusual for multiple such weather events to take place in a small window.