SHANGHAI — Health authorities in China are investigating one of the nation’s biggest vaccine makers after eight infants died in the past two months following injections that were meant to immunize them against hepatitis B.

The government said this week that it had suspended the use of millions of doses of a hepatitis B vaccine produced by the manufacturer, Shenzhen Kangtai Biological Products. Government inspectors have been sent to examine the company’s facilities.

Six of the deaths have been linked to vaccines produced by Shenzhen Kangtai; the two other infant deaths occurred recently after the use of a hepatitis B vaccine produced by another drug maker, Beijing Tiantan Biological Products. The government did not say whether any action had been taken against Beijing Tiantan or its vaccines. Investigators have not determined the cause of the deaths or linked them directly to the injections, but the cases come at a time of growing public concern in China about food and drug safety problems.

In recent years, China has been troubled by a series of scandals, including tainted rice and milk and the mysterious appearance of thousands of dead pigs floating in the Huangpu River in Shanghai. China has vowed repeatedly to crack down on food and drug safety violations and has moved to strengthen the powers of health officials.