The Health Ministry's previous count stood at three deaths, with more than 50,000 babies sickened.
Six babies had possibly died from drinking tainted milk powder, the statement said, with four of the cases recorded in the provinces of Jiangxi, Zhejiang, Guizhou and Shaanxi, and the other two in Gansu province in the northwest.
The ministry did not give further details, nor say whether the three earlier reported deaths were included in the new total.
The tainted milk, China's worst food safety scandal in years, prompted authorities to announce a complete overhaul of the country's dairy industry to improve safety.
The scandal highlighted the widespread practice of adding melamine - often used in manufacturing plastics - to watered-down milk to fool protein tests. Melamine is rich in nitrogen, which registers as protein on many routine tests.
Investigations also discovered it was being added to animal feed after finding melamine-spiked eggs.
Melamine poses little danger in small amounts but larger doses can cause kidney stones and renal failure.
The scandal was first reported in September, but the government has said that Shijiazhuang Sanlu Group Co., a dairy firm at the center of the crisis, knew as early as last year that its products were tainted with melamine and that company and local officials first tried to cover it up.
