US health authorities told consumers to avoid eating products that contain peanut butter until they can determine the scope of an outbreak of salmonella food poisoning that may have contributed to six deaths.
"We urge consumers to postpone eating any products that may contain peanut butter until additional information becomes available," said Dr Stephen Sundlof of the Food and Drug Administration's Center for Food Safety.
The FDA also said Hy-Vee Inc was voluntarily recalling bakery products distributed in seven states because they contained peanut butter that could be contaminated with salmonella.
As of Friday night, 474 people had been reported infected by a salmonella outbreak linked to peanut butter by public health authorities in 43 of the 50 US states, the Centers for Disease Control and Prevention said.
Twenty-three percent of the known cases had resulted in hospitalizations and the infections may have contributed to six deaths.
The company at the centre of the case, Peanut Corporation of America, said it had been informed by the Food and Drug Administration that some samples of its products had tested positive for a salmonella strain that may have originated in a Blakely, Georgia, peanut processing plant.
The recalled peanut butter was sold in bulk and none of the peanut butter or peanut paste being recalled is sold through retail stores, PCA said.