SALT LAKE CITY — Utah health authorities were investigating Monday what triggered an E.coli outbreak in a mostly-polygamous community on the Utah-Arizona border after the bacteria killed two children and sickened four others.

Early indications suggest the E.coli may be linked to contaminated food or exposure to animals — not the town of Hildale’s water supply, said David Heaton, spokesman for the Southwest Utah Public Health Department. He said it appears isolated to one neighborhood.

Heaton said he can’t releases the names or ages of the deceased children, or say if they are related, due to privacy concerns.

He said they died in the past two weeks after getting hemolytic uremic syndrome, also known as HUS, which causes kidney damage.

E.coli can cause diarrhea, cramps, nausea, headaches or other symptoms.

Utah Department of Health spokeswoman Jenny Johnson said deaths from E.coli are pretty rare with an average of only one person a year dying from the illness in Utah, a state of about 3 million people.

There are 80 to 100 cases per year in Utah of a strain of E.coli that have a toxin called Shiga that makes people sick, Johnson said.

The four other people who came down with E.coli in Hildale are children and adults but Heaton didn’t have the exact breakdown. He declined to release their conditions but said they’ve all received medical care.

The sister towns of Hildale, Utah and Colorado City, Arizona, are home to a polygamous group known as the Fundamentalist Church of Jesus Christ of Latter-Day Saints. It is a radical offshoot of mainstream Mormonism, which disavowed polygamy more than 100 years ago.