At least six small children contracted HIV through doctors' negligence in a Kazakh city, officials said Thursday. Nine other children are believed to have been infected.

The 15 children, all under 3 years old, were believed to have contracted the virus that causes AIDS while receiving treatment, including injections and blood transfusions, in hospitals in Shymkent, Anatoliy Belonog, the Health Ministry's chief epidemiologist, said in televised remarks.

All 15 tested HIV-positive after initial tests; repeat tests on six confirmed the initial diagnosis and the results for the other nine were expected shortly, he said.

One child received blood from several donors, in violation of regulations, and some of the others received direct transfusions of blood from donors who were not checked for HIV or other illnesses, Health Ministry official Ualikhan Akhmetov said.

Officials said prosecutors were investigating and that any medical staff found responsible for the infections would face criminal charges

The Health Ministry said the infected children would be provided with treatment free of charge and their families would received financial aid.

According to health officials, the Central Asian nation recorded 828 new HIV carriers and 70 AIDS patients in the first six months of this year, a 70 percent increase in new cases over 2005.