COLUMBUS, Ohio — Officials in Ohio say 19 people whose illnesses delayed an NCAA swimming and diving meet had norovirus, and were on the same flight from Dallas.

Columbus health department spokeswoman Amanda Ford says the gastrointestinal ailment was identified from samples from four of those who got sick. She says investigators are looking into not only their American Airlines flight to Columbus Monday but also other possible links, such any airport food they ate.

The 18 athletes and a coach from three schools were treated at a hospital and released. The outbreak led the NCAA to delay its Division I men's swimming and diving championships at Ohio State by one day.

American Airlines spokesman Tim Smith says it does not believe there's any connection to its flight.