Fifty-five small children in hospital in Kazakhstan have been infected with HIV because of "plain negligence", the country's health minister said.
The children were infected while being treated at a hospital in the southern city of Shymkent, Erbolat Dosayev was quoted as saying.
Officials are seeking 17 people, suspected of carrying the HIV virus, who donated blood used at the hospital.
Prosecutors are investigating whether to bring criminal charges.
"There was plain negligence, and there were violations of medical norms," Mr Dosayev told reporters.
Tests have been carried out on half of nearly 10,000 children under the age of three, who had been treated at the hospital and were thought to be at risk, he said.
The first cases of HIV among the children were reported in the summer.
Members of parliament have called for the resignation of Mr Dosayev and regional health care officials.
Mr Dosayev said he would resign if "it turns out that I am largely responsible".