Health officials are investigating what caused 47 people to fall ill at a Christian campground in San Bernardino County.
On Saturday night, campers at the Oak Glen Christian Conference Center in Yucaipa began suffering from nausea, vomiting and diarrhea, said Lana Cao, spokeswoman for the San Bernardino County Department of Public Health.
When first responders arrived, they provided medical aid to 20 people for an unknown illness; 13 were taken to hospitals, according to the California Department of Forestry and Fire Protection's San Bernardino County Unit.
The number of patients has since grown to 47.
The camp has remained closed since Saturday night as investigators try to determine the cause of the outbreak, Cao said.
Inspectors with the county's Division of Environmental Health Services are working with the health department's communicable disease section.
Members from the Connecting Point Community Church, Grace and Love Church and the Church in Irvine were visiting the campground during the weekend, according to the Oak Glen Christian Conference Center's Facebook page.