WASHINGTON – Cans of recalled food are bursting, swollen with bacteria that cause botulism.

The bursting cans were among those being held by Castleberry’s Food Co., which last week announced a massive recall that now includes more than 90 potentially contaminated products, including chili sauces and dog foods.

News about the bursting cans gives new urgency to warnings from federal health officials to get rid of the recalled cans from pantries and store shelves.

Spot checks by the Food and Drug Administration and state officials are turning up recalled products for sale in convenience stores, gas stations and family-run groceries.

The FDA has found recalled products for sale in roughly 250 of the more than 3,700 stores visited in nationwide checks, according to figures the agency provided to The Associated Press.

Four people have been sickened and hospitalized by the contaminated food, according to the Centers for Disease Control and Prevention. The recall covers potentially tens of millions of cans of food; officials fear the tally will grow.

FDA investigators believe Castleberry Food failed to properly cook some or all the products, allowing Clostridium botulinum bacteria to survive the canning process.

The bacteria produce a toxin that causes botulism, a muscle-paralyzing disease.