A possible salmonella contamination has prompted Trader Joe’s to recall some cashews.

The grocery store chain issued a statement about the recall late last week, saying that one particular kind of Trader Joe’s Raw Cashew Pieces could be contaminated with the bacteria.

The cashews are marked “BEST BEFORE 07.17.2016TF4,” the company said, and were distributed to stores in 30 states across the country, as well as the District of Columbia.

It wasn’t clear exactly how many packages were included in the recall.

Trader Joe’s said it learned of the possible contamination from a supplier, but didn’t elaborate.

A recall notice on the Food and Drug Administration website says Heritage International (USA) Inc. was voluntarily recalling the cashew lot after routine lab tests found salmonella in it.

The bacteria can cause people to fall ill.

Trader Joe’s said it hasn’t received any reports of anyone getting sick from the cashews, though it has stopped selling all Trader Joe’s Raw Cashew Pieces in its stores pending an investigation.

The grocery chain encourages anyone who bought the cashews marked “BEST BEFORE 07.17.2016TF4” to return them for a full refund or throw them out without eating them.

According to the CDC, salmonella sickens about 1.2 million Americans every year. Symptoms include diarrhea, fever and abdominal cramps, and most people fully recover in 4 to 7 days. In extreme cases, though, infections can spread beyond the intestines and become more severe.

The bacteria leads to about 450 deaths and 19,000 hospitalizations every year, the CDC says. Children, older adults and people with weak immune systems are particularly at risk.