The United Nations on Friday increased its appeal for Philippines typhoon relief by nearly 16 percent to 348 million U.S. dollars with a further rise likely as aid organizations move into top gear in the face of a disaster that reportedly killed more than 5,000 people and affected a total of 13.25 million others.

"A massive disaster like this requires a massive response," the UN under-secretary-general for humanitarian affairs, Valerie Amos, said at a news conference here just after returning from her second visit to the area in a week in the wake of the devastation wrought by Typhoon Haiyan on Nov. 8.

"Much more needs to be done. Food, clean water and shelter remain the top priorities," said Amos, who is also the UN humanitarian coordinator. "Vast numbers of vulnerable people are still exposed to bad weather and need basic shelter."

"Families who have lost their homes will need substantial longer-term support from the international community to ensure they have the means to rebuild their houses," she said.

The Filipino government on Friday raised the death toll from Haiyan to more than 5,200 as it still tries to verify the total number of dead and missing, with communities on remote islands or in mountainous areas still not reached.

More than 5 million of those affected are children, and more than 4 million people have been left homeless with over 1 million homes destroyed.

When it first launched its so-called flash appeal on Nov. 12, the UN sought 301 million U.S. dollars, an amount that as of Friday is nearly 39 percent funded at 134 million dollars, UN officials said.

Amos noted that the new amount of 348 million U.S. dollars is expected to rise as there are still communities yet to be reached, and a major review of the appeal is slated for the first week in December.

"The logistical challenges have been enormous, with many roads blocked and airports unusable in the first few days," she said. " The impact on essential services, hospitals, banks and markets, as well as the lack of fuel, transport, water and power, made it very difficult to scale up aid as quickly as was needed."

On her latest visit to the Asian island country, Amos said, "I have seen and heard harrowing tales of desperate need and profound loss. I also heard reports of immense bravery and heart-warming compassion."

"I saw how the international community pulled together with the communities and authorities to work out how to overcome major obstacles, and saw more and more people being reached with basic assistance," she said.

The UN World Food Program (WFP) has reached over 2.5 million people with basic food aid, more than 130 local and foreign medical teams are providing emergency treatment, and thousands of tarpaulins and plastic sheets have been distributed, but vast numbers of vulnerable people are still exposed to bad weather and need basic shelter.

"Families who have lost their homes will need substantial longer-term support from the international community to ensure they have the means to rebuild their houses," Amos said.

"I am very concerned that some 1.5 million children are at risk of acute malnutrition and close to 800,000 pregnant and nursing mothers need nutritional help," she said. "People living with chronic disease and other vulnerable groups need medication and specialist care."

She thanked the international community for its "great solidarity" with the Philippines people and donors for their generous and rapid response, but highlighted the global strain on UN supply lines in responding to multiple emergencies.

"We count on donors to help us rapidly address this shortage of supplies," she said. "The people of the Philippines deserve our unwavering support as they survive this crisis, start rebuilding their lives and have hope for a better future." Endi