SunOpta said it's voluntarily recalling a "limited" number of sunflower kernel products made at its Crookston, Minn., plant due to potential listeria contamination.

Many of the recalled items are sold under the popular Planters brand, which is owned by food giant Kraft Heinz. Others were sold under the Dakota's Best Biggy'z label.

There have been no reports of illness from the recalled products.

Listeria monocytogenes bacteria can cause listeriosis, a potentially deadly infection. It strikes hard at pregnant women, newborns, older adults and people with weakened immune systems, according to the Centers for Disease Control. About 1,600 illnesses and 260 deaths are caused annually by listeriosis in the U.S.

SunOpta, a Toronto-based ingredient supplier with a large presence in Minnesota, discovered the listeria problem after a call from one of its corporate customers. The customer tested a batch of sunflower nuts that came up positive for listeria, said Rob Litt, a SunOpta spokesman.

SunOpta voluntarily shut down its Crookston plant on April 21, Litt said, though it's expected to reopen soon. "We believe we have found the issue and are working with the [U.S. Food and Drug Administration] to resolve it."

Litt said sunflower nut production includes a "kill step" to zap listeria, but the contamination appears to have occurred after that point.

The recalled products were made between Feb. 1 and Feb. 19, and were shipped to distribution centers in Illinois and North Dakota. From there, they may have been distributed nationwide.

The recalled items were sold in clear printed plastic packages. They include nine lots of Planters sunflower kernels sold in 3-ounce bags with a UPC code of 029000012714 and "best buy" dates of March, 6, 7, and 8, 2017; and one lot of Dakota's Best Biggy'z roasted and salted kernels sold in 16-ounce bags with the UPC code of 834648001484 and the best by date of Feb. 11, 2017.