Six patients have died of gastroenteritis caused by a norovirus outbreak at Shunkokaihigashi Hospital in Nichinan, Miyazaki Prefecture, hospital officials said Sunday.

The victims — all men aged between 78 and 88 — were among 44 patients and staff who came down with symptoms of the illness, including vomiting and diarrhea, the officials said. All six were bedridden.

The health ministry has issued a nationwide warning about the norovirus because infections are approaching the record high set in 2006.

Elderly people and children are considered those most vulnerable to the virus, which spreads via physical contact, food consumption or through the air.

As of Sunday, 11 people, including hospital staff, were being treated. Five patients aged 76 to 90 are in serious condition.

Shigekazu Miyaji, the hospital's director, apologized for the late report on the outbreak and said the staff didn't initially think it was being caused by the norovirus.

The hospital began looking more closely at the norovirus when cases quadrupled from four to 16 on Dec. 16. It then reported its observations to prefectural medical authorities.

The first norovirus fatality occurred on Dec. 14, but the hospital didn't start reporting the deaths until Dec. 22, when the sixth person died.

In a separate development, 1,184 people at 372 Yamanashi-based companies developed food poisoning symptoms after eating boxed lunches bought from catering service Runrun Lunch, based in Kai, prefectural officials said.

The norovirus surfaced in 32 people, including at Runrun, but none is critically ill so far.

In Oita, meanwhile, 27 people began complaining of diarrhea and other systems after eating at a restaurant in the capital named Gento.

City officials said that 11 of the people, who were in their 20s to 70s, had contracted the norovirus but none is in serious condition.

Both Runrun and Gento have suspended business.