Chicago Breaking News reports that at least four people were hospitalized and 53 others reported illnesses after attending wedding parties this month at a banquet hall in south suburban Mokena, Illinois, leading Will County health officials to try to determine the cause.

The Health Department is looking for others who may have gotten sick after attending weddings at Di Nolfo’s Banquet Inn and Catering on July 16 and 17.

Health officials believe the source of the illness is norovirus. Health officials collected and tested food from Di Nolfo’s, 9425 W. 191st Street, but did not find any significant violations. None of Di Nolfo’s employees have reported illnesses, officials said.