PHNOM PENH, Cambodia — Hospitals in the Cambodian capital are struggling to cope with an unusually high number of infants apparently sick with influenza, officials said Wednesday.

More than 1,000 children, aged between 2 months and 5 years old, have been admitted to Phnom Penh hospitals in recent days with acute respiratory infections, said Deputy Health Minister Heng Tay Kry.

"This is quite unprecedented and strange this year. The situation is still under our control, but we have to be ready" for it to worsen, he said.

The disease appears to be a form of human flu, not the bird flu that has killed dozens of people in neighboring countries, he said.

He said the patients had arrived at the hospitals with heavy coughs, high temperatures and gasping for breath, requiring them to be given oxygen immediately.

The steady flow reached a critical point last weekend, when the Kuntha Bopha children's hospital, which has just 200 beds, received more than 500 patients.

"One bed was occupied by three to four patients," Heng Tay Kry said, adding that 100 extra beds were brought to three other hospitals in Phnom Penh, where patients were shifted.

Megge Miller, an epidemiologist working at the World Health Organization in Cambodia, said tests were being conducted to determine the pattern of the illness.

Cambodia, one of the world's poorest countries, faces an uphill battle to improve health services for its 14 million people. About 63,000 Cambodian children die every year from preventable diseases such as malnutrition and diarrhea.