Cambodian officials say they are investigating a health clinic in a small village where more than 100 people have now tested positive for HIV.
Authorities say they fear the repeated use of an infected needle could be causing the devastating outbreak in northwestern Battambang province.
A total of 106 people, including children, have now tested positive for the disease. About 800 of the 2,000 residents in Rokar village have been screened so far.
Teng Kunthy, secretary-general of the National AIDS Authority, told reporters Wednesday he is concerned about further spread of the disease and its effects on the lives of those who have contracted it.
He said at least 25 of the infected people are under the age of 15.
Testing continues in the village, located eight kilometers outside the provincial capital of Battambang.
Cambodia has made progress in lowering its rate of HIV and AIDS infection from a high of nearly two percent in 1998. The country is aiming for a zero-percent infection rate by 2020, down from its current rate of about 0.7 percent.
This report was produced in collaboration with the VOA Khmer service.