The latest death was a 44-year-old man, who had been hospitalised Wednesday and died Friday, the Thanh Nien (Young People) newspaper said.
The paper quoted sources from the city's health department saying the man had drunk locally-produced rice alcohol.
Tests showed the quantity of methanol in the man's blood samples was high, the paper said.
Vietnamese, mostly men, drink about 250 million litres of home-made rice alcohol every year, said website VietnamNet.
The figure accounts for 90 percent of the total alcohol consumed across the 86 million population of Vietnam.
The Health Ministry has sent teams to check the quality of alcohol in major cities, and much of which was discovered containing high volumes of methanol.