China has launched a probe into deaths connected to Hepatitis B vaccinations in the country, state media reported on Monday, following yet another death in Shenzhen last week when a newborn baby died about 70 minutes after he was inoculated with the vaccine, taking the total toll to seven.

According to a report in Xinhua, at least four deaths from Hepatitis B inoculations have been reported since November from the southern province of Guangdong, 930 miles from Shanghai, the largest city by population in the world. According to authorities, two deaths were reported in Hunan Province in central China, and one death was reported in southwestern Sichuan province. 

China’s health, food and drug authorities and the National Health and Family Planning Commission jointly issued a circular Friday, ordering hospitals to stop using Hepatitis B vaccines manufactured by Shenzhen-based Biokangtai, which allegedly caused the deaths. The health ministry is investigating the deaths and the company’s products, China Daily reported. Most of the infant deaths occurred within an hour to two days from the time of vaccination. 

China has witnessed several cases of deaths among children and infants resulting from contamination in food and vaccines, and infections contracted during the vaccination process.

At least six children died in 2008 after drinking milk contaminated by melamine, an industrial chemical. In 2011, at least 10 children in Henan and Anhui provinces contracted Hepatitis C after they were infected by contaminated syringes used for vaccination.

Biokangtai, in a statement carried by state media last week, had said that it “rigorously followed safety rules but that they were testing the batches suspected of causing the deaths,” Reuters reported.

Biokangtai, has a 60 percent share of the market and sells 10 million vaccines a year in China, according to The Time Weekly.