More than 160 people claim they became ill after eating at an Olive Garden restaurant last weekend, health officials said Friday.

"At this point we're continuing to gather information," Marion County Health Department spokesman John T. Althardt said. "We're trying to isolate what the cause of the illnesses might be."

Patrons at the Olive Garden on East 82nd Street reported becoming ill after eating there Saturday, Sunday and Monday, he said. They said they had symptoms including nausea, vomiting, fever and diarrhea.

Inspectors met with restaurant managers on Tuesday and found no health code violations. Health officials were collecting leftover food and stool samples from those stricken to try to pinpoint the source of the illness, Althardt said.

Frank Williams said he became sick Tuesday morning after eating at the Olive Garden over the weekend.

"It was my wife's birthday party dinner and the only thing that everyone had was a little cake," he told WRTV-TV. "And that seemed to be a fairly unlikely candidate to cause everyone to get sick."

Seven of the eight people in his party fell ill, he said.

A spokesman for the restaurant based in Orlando, Fla., was not immediately available for comment Friday morning. Olive Garden is owned by Darden Restaurants Inc., which also operates casual dining chains Red Lobster, Bahama Breeze and Smokey Bones.