After reports of a mystery illness, a Mississippi convention facility has been cleaned and disinfected before entertaining additional guests.

According to news reports, officials from the Mississippi Coast Coliseum and Convention Center say their building has been scrubbed and sanitized after dozens of people who attended a Mardi Gras Ball at the center last weekend reported gastrointestinal problems.

People who attended an event a week earlier in the same part of the facility also reported the same symptoms.

Mississippi Health Department officials are reportedly investigating the possibility of a norovirus at the center, but haven’t identified the source of the illnesses.

Norovirus is a very contagious virus that causes vomiting and diarrhea, according to the Center for Disease Control and Prevention.