Hundreds of people have fallen sick across Japan after eating frozen food that may have been tainted with a pesticide.

Food maker Maruha Nichiro Holdings used full-page ads in major newspapers on Wednesday apologising and warning consumers not to eat any of the tainted food. 

"The products will have a strong smell and eating them may cause vomiting and stomach pain," it said in the notice, which included 51 colour photos of the products, including pizza, croquettes and pancakes manufactured at a factory north of Tokyo.

The health ministry said it had confirmed 556 people suffering such symptoms after eating those products as of late Tuesday. In a notice on its website, it ordered Maruha Nichiro to recall all potentially affected products and to inform the public about the situation.

The company began recalling 6.4 million packages of various frozen foods on Dec 29, saying it found some were tainted by high levels of malathion.

No life threatening illnesses 

Malathion is a pesticide used in farming and gardening and also to kill fleas on animals and people. At high enough concentrations, it can cause death. 

There have been no reports of life-threatening illnesses from Maruha's products, but police are investigating how the items were reportedly contaminated by up to 2.6 million times the allowed limit. 

Kyodo News agency said Wednesday that its tally found 909 people sickened after eating the Maruha products, while public broadcaster NHK said information from local governments showed 356 people affected.

Both reports said it was unclear if consumption of the tainted products was directly responsible for the illnesses, and the health ministry said it had not detected malathion in nearly three dozen cases tested.

Source: AP