The Tulsa City-County Health Department said three children have been sickened by E. coli bacteria.

Agency spokeswoman Melanie Christian said the department’s lab confirmed the cases in the children, who are under 10 years old. Christian said two of the children were hospitalized but one has gone home.

She says two of the children are siblings.

Agency officials are still investigating how and where the children contracted the illness.

Christian said two of the children go to daycare at the Boston Avenue United Methodist Church in Tulsa, but that’s the only common point of contact.