A multistate outbreak of salmonella likely caused by contaminated onions has sickened nearly two dozen Minnesotans.

The Centers for Disease Control and Prevention (CDC) warned Wednesday that fresh whole red, white and yellow onions imported from Chihuahua, Mexico, and distributed by ProSource Inc. are the likely source of the outbreak. Federal health officials advise people not to buy or eat these onions.

They also advise people to throw out any whole red, white or yellow onions that don't have a sticker or packaging.

"If you can't tell where the onions are from, don't buy or eat them," the CDC warned. The agency also advised using hot, soapy water or a dishwasher to clean surfaces or containers that came in contact with the onions.

State health officials reported that 23 Minnesota residents, ranging in age from 7 to 77, were sickened between Aug. 8 and Sept. 18. Four were hospitalized. No one has died.

The national outbreak has sickened 652 people, including 129 who had to be hospitalized, in 37 states.

ProSource indicated the onions, which were sold to restaurants and grocery stores, were last imported on Aug. 27. They can last up to three months in storage and may still be in homes and businesses, according to the CDC.

Investigators are trying to determine if other onions and suppliers are linked to the outbreak.

People infected with salmonella often experience diarrhea, fever and stomach cramps. Symptoms usually begin six hours to six days after ingesting the bacteria. Most people recover without treatment within four to seven days.