UN Humanitarian chief Valerie Amos has called for longer-term support for the Philippines people, millions of whom are affected by the devastating Typhoon Haiyan, a UN spokesperson said Thursday.

"Amos warned that people left without homes will require substantial longer-term support from the international community to ensure they are provided with the means to rebuild their houses, " Fahran Haq, associate spokesman for the secretary-general, said at a regular news briefing here.

Of the 4.4 million homeless people, more than 387,000 people are still staying in evacuation centers across the six affected regions in the Philippines, according to the spokesman.

Amos on Thursday wrapped up a three-day visit to the Philippines in an effort to promote humanitarian aid.

The Philippines government estimated that 13.25 million people have been affected by the typhoon by Wednesday, including some 5. 4 million children, many of whom were facing serious health and safety risks, Haq said, adding that a measles, vitamin A and polio vaccination campaign is set to start in the country Monday.

More than 4,000 people are believed to have been killed and 18, 000 injured when Haiyan, the strongest typhoon ever recorded, made landfall in the central Philippines on Nov. 8 and the sea surged ashore like a tsunami.