Seven people, most of them elderly women, died after eating pickles contaminated with E. coli in northern Japan, officials said Sunday, in the country's deadliest mass food poisoning in 10 years.

A total of 103 others have been made ill after eating the same lightly pickled Chinese cabbage produced in late July by a company in the city of Sapporo, according to health bulletins issued by the local government.

Of the dead, six were elderly women who ate the pickles at nursing homes in Sapporo and in another city on Hokkaido island. A four-year-old girl died on August 11 in Sapporo.

In the city of Ebetsu, a woman centenarian died early Sunday from multiple-organ failure, nine days after she was hospitalised, a Hokkaido regional health official said.