Fourteen people suffered from food poisoning in April due to tap water supplied by the town of Kanna, Gunma Prefecture, authorities announced on Tuesday.

According to the prefecture, the cluster involves 10 men and four women ranging from children under the age of 9 to individuals in their 80s. Reported symptoms include diarrhea, abdominal pain and fever.

None of the people have been hospitalized and all are recovering, the prefecture said.

On April 21, the town of Kanna contacted the prefectural health center to report that several residents of the Aibara district had visited a medical institution between April 14 to 19 with symptoms including fever and diarrhea.

An investigation by the health center revealed that the only common factor among those affected was the consumption of tap water.

Following the report, the town of Kanna tested the water from the reservoir supplying tap water to the Aibara district and found that the results violated the water quality standards outlined in the Water Supply Act.

Furthermore, campylobacter — a type of bacteria that can cause diarrhea — was detected in stool samples from multiple symptomatic individuals.

The town believes the cause to be agricultural water flowing into the reservoir, NHK reported. As a preventative measure, local authorities have advised residents not to drink tap water and have been giving out bottled water in the affected area.

The town also announced that the water supply has been replaced, though investigations are still ongoing. While the water can be used for daily use, residents are urged against drinking it.

“We apologize for the inconvenience caused to the residents of Aibara and all other concerned parties,” the town said in a statement on its website.