Jolly Time Microwave Pop Corn was pulled from stores in four states after dozens of people got sick, but the Food and Drug Administration said tests found no link between the snack and the illness.

"We have cooperated fully in the investigations and we have done everything we have been asked to do," said Jim Fowler, vice president of the American Pop Corn Co. The company is based in Sioux City."We are at a loss to explain what caused the reported illness, but we are relieved to know the testing has shown it wasn't our product," he said.

The company removed two lots of the popcorn from store shelves in New Hampshire, Vermont, Maine and New York, where more than 100 people said they suffered severe vomiting and diarrhea soon after eating the popcorn.

Two more cases were reported Tuesday in North Dakota.

Chris Lecos, a Food and Drug Administration spokesman in Washington, said the FDA collected samples of the popcorn from stores and from some of the stricken customers.

"We have not been able to identify any kind of contaminant that would link this product to any of the reported illnesses," he said.

Fowler said tests were also done by state authorities and a lab hired by the company, and all turned up negative.

The FDA, state health agencies and the manufacturer continued to investigate.