More than 55 people, including children, fell ill with suspected food poisoning at a homeless shelter in Salt Lake City on the weekend.

Officials investigating into the issue said that ambulances and a bus were immediately sent to the shelter on Sunday to take the ill to hospitals for treatment.

Those sickened reported nausea, vomiting, abdominal pain and diarrhea, according to Salt Lake City Fire Department spokesman Jasen Asay.

All the homeless people were later released after being treated in emergency rooms, Asay added.

Officials said that a telephone call to the road Home shelter was not returned on Monday. The shelter is divided into two sections. One section is occupied by single men and women and the one is where families live. The latter has kitchens that are used by occupants.

Ilene Risk, an epidemiologist at the Salt Lake County Department of Health, said those who check into Road Home often get food from a nearby soup kitchen or from other such facilities in the city.

The source of food contamination could not be immediately identified but investigators are still deeply investigating into the issue to find a clue, she said.

Food might have got contaminated by pathogens related to temperature, environmental contamination and unclean containers, among other causes, Risk said.

As per Utah law, charitable organizations that provide food to disadvantaged groups are not required to have food-handling permits.

Danielle Stamos, public relations director with the Catholic Community Services of Utah, said, “To hear that 50 of our homeless friends we sent to the hospital out of kindness out of people trying to do service is the worst thing we can think of”.