Rangoon, Burma — Police barred foreign aid workers from reaching cyclone survivors in hard-hit areas yesterday, while emergency food shipments backed up at the main airport for Burma’s biggest city.

Relief workers reported some storm survivors were being given spoiled or poor-quality food rather than nutrition-rich biscuits sent by international donors, adding to fears that the ruling military junta in the Southeast Asian country could be misappropriating assistance.

U.N. officials warned that the threat was escalating for the 2 million people facing disease and hunger in low-lying areas battered by the storm unless relief efforts increased dramatically.

Ten days after the tempest, reaching the worst-affected areas was getting more and more difficult.

Checkpoints manned by armed police were set up yesterday on roads leading to the Irrawaddy River delta and all international aid workers and journalists were turned back by officers who took down their names and passport numbers. Drivers were interrogated.

“No foreigners allowed,” one policeman said after waving a car back.

Supplies piled up at Rangoon’s main airport, which does not have equipment to lift cargo off big Boeing 747s. It took 200 Burmese volunteers to unload by hand a plane carrying more than 60 tons of relief supplies, including school tents, Dubai Cares, a United Arab Emirates aid group, said.

A report from a meeting yesterday of the U.N. center overseeing logistics said the airport was a bottleneck in the aid effort. “Discharging operations at Yangon airport are hampered by limitations of handling equipment, fuel availability, and worsening weather conditions,” it said.

The report said Britain’s Department for International Development had offered to send in machinery for unloading jumbo jets and other aircraft.