A senior UN official on Wednesday called for a doubling of international aid to nearly 700,000 people displaced by conflict and floods in the southern Philippines, many of whom are living in dire conditions.

Catherine Bragg, the United Nations assistant secretary-general for humanitarian affairs, said the recurring nature of the violence on the island of Mindanao left whole communities unable to farm or get proper medical care.

"I am deeply concerned by the impact of cycles of displacement, particularly those caused by armed confrontations between government forces and armed groups, and clan fighting," she told reporters after a visit there.

She met a family who were chased off by floods after being forced to move by armed conflict twice over five years, and a former farmer who had had to switch to fishing to support his family.

"In Mindanao, a lot of basic human needs are not satisfied at the moment," Bragg said.

She appealed to the government and the various armed groups in the region to refrain from hindering the delivery of humanitarian assistance.

"As humanitarians, the aid we provide is totally neutral and totally impartial," she said.

"Emergency response must be granted unhindered."

Three International Committee of the Red Cross workers were kidnapped but later freed unharmed by Islamist militants in the southern province of Sulu in 2009.

A cargo truck helper was also killed when unknown gunmen ambushed a truck transporting UN World Food Programme food aid to residents displaced by conflict in the southern province of Lanao del Sur in 2008.

Bragg said the UN would call for $37.9 million in humanitarian aid next year for Mindanao, where a decades-long Muslim rebellion, banditry and Islamist militant attacks have left tens of thousands dead and left many others leading precarious lives.

The UN and its aid partners have managed to deliver about $17.98 million to Mindanao this year, well short of the $33.3 million target for 2011, she added.

President Benigno Aquino resumed a ceasefire and peace talks with the Moro Islamic Liberation Front, the country's largest guerrilla group, after he was elected last year.

However, Bragg said frequent fighting by armed Muslim clans continued to cause evacuations.

Widespread floods in June meanwhile swelled the numbers of those needing help, with some communities suffering from both the conflict and the floods, she said.

"In Mindanao... nearly 700,000 people are still in dire need of humanitarian relief, protection and livelihoods support," she said.

Bragg said she expected the number of UN and other aid workers in the region to rise as aid is ramped up next year, but said she did not have exact figures.

"A major way by which the UN can offer protection is by its presence -- simply being somewhere and making sure that those who want to perpetrate actions of violence would not be able to do so unseen by outsiders."

More than 50 UN and other aid groups operate in Mindanao, Akiko Yoshida, humanitarian affairs officer of the Philippine unit of the UN Office for the Coordination of Humanitarian Affairs, told AFP.