WASHINGTON — Hundreds of thousands of pounds of frozen food recalled amid an E. coli scare may have been served in schools, according to the company that manufactured the items.

Buffalo, N.Y.-based Rich Products Corp. has over the past two weeks recalled 10 million pounds of frozen food items after 27 E. coli illnesses in 15 states were linked to their foods. Of that, the company estimates that about 3 million pounds may still be in the marketplace and approximately 300,000 pounds may have ended up in school lunchrooms, a company spokesman said.

Dwight Gram of Rich Products said the main items shipped to schools were labeled as pizza dippers and pepperoni pizzatas.

E. coli infection can cause mild diarrhea or more severe complications, including kidney damage. According to the federal Centers for Disease Control and Prevention, 81 percent of the people who fell ill were under the age of 21. Nine people were hospitalized and two have developed hemolytic uremic syndrome, a type of kidney failure that can have lasting effects.

The strain of E. coli linked to the Farm Rich brand products is rare, and some laboratories still can’t identify it. Because of that, the CDC said, many illnesses may not have been identified.

Health officials have so far directly linked the outbreak strain to two different Farm Rich brand products — frozen mini pizza slices and frozen chicken quesadillas. Samples of the strain of E. coli were collected from those products in the Texas and New York homes of two people who became ill.

It’s not clear yet whether any illnesses are linked to foods shipped to the schools.

Rich Products two weeks ago announced a voluntary recall of certain Farm Rich and Market Day brand products because of the possible E. coli contamination. Last week, the company expanded that recall to include everything made at its Waycross, Ga. plant — a total of 10 million pounds of food. Products manufactured at other plants weren’t affected.

At least one school district has already warned parents that food served in its cafeterias was recalled because of possible E. coli contamination.

A spokeswoman for Harford County, Md. schools said last week that Rich Products had notified the district that it had recalled its pepperoni pizzatas. Some of the food had already been served in cafeterias.

Gram, the spokesman for Rich Products, said school foods may be safer than those purchased by individuals because they are more likely to be well cooked. Cooking items thoroughly can kill E. coli.