Two U.S. military planes loaded with supplies, including drinking water, landed Wednesday in the former capital Yangon. The first flight arrived Monday following strenuous international protests against the junta's tight grip on the country formerly known as Burma.

Three more flights were to follow Wednesday, Xinhua reported.

The U.N. Office for the Coordination of Humanitarian Affairs warned unless more access is granted to allow aid to flow more quickly, another catastrophe from infections and other risks could result, the U.N. News Center reported.

Despite some progress in the relief effort, OCHA spokeswoman Elizabeth Byrs said the United Nations and its partners have been able to reach about 270,000 of the 1.5 million survivors 12 days after the storm.

She called for an air and sea corridor to channel aid in large quantities.

Two human rights activists said 90 percent of Myanmar's population lives in poverty. They said immediate international help is needed both in the short and long term.

The Democratic Voice of Burma claimed Myanmarese officials and supporters have been taking relief supplies from international donors and selling them for personal gain.