SALT LAKE CITY (AP) — Utah health authorities say they have confirmed an additional case of E.coli connected to an outbreak that previously killed two children in a mostly polygamous community on the Utah-Arizona border, bringing the total number of cases to 12.

Southwest Utah Public Health Department spokesman David Heaton tells the Salt Lake Tribune that authorities hope the outbreak has nearly run its course. It surfaced publicly nearly a month ago.

The department put out a call on Facebook post for information on any untreated diarrhea cases since June 1.

The cause of the outbreak is under investigation, but contaminated drinking water has been ruled out.

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.