One person has died and nearly 150 others left ill after eating grilled eel prepared by a restaurant chain and sold at a department store near Tokyo, officials said. Among those sickened, two were taken to hospital.

Keikyu Department Store said 147 customers as of Monday had reported symptoms such as vomiting and diarrhea after eating grilled eel dishes sold in the grocery section of the department store based in Yokohama, near Tokyo, between July 24 and July 25.

Japan has a tradition of eating roasted eel as a tonic for the heat during the hottest days of summer.

A woman in her 90s died after developing symptoms, but her exact cause of death is being further investigated, the Yokohama city health center said. Two other people were hospitalized, but the symptoms of others affected were milder, it added.

The only common denominator among the sickened was the grilled eel, sold separately or as part of box lunches served with rice, prepared by the Tokyo-based restaurant chain Nihonbashi Isesada, and sold at the department store, the health center said. More than 1,700 servings of grilled eel were sold at the shop, Keikyu officials said.