Four teenage boys were caught Friday buying household cleaners that could be used to make explosives at a Windham supermarket.

Lt. David DeGruchy of the Windham Police Department said the department was called April 11, at 8:30 p.m., after employees at the Hannaford supermarket on Roosevelt Trail observed the boys, all age 15, buying over the counter products and behaving suspiciously.

“When they are mixed, they could cause an explosion,” said DeGruchy. He declined to say what products the boys were buying out of fear of others trying to buy them for the same purposes.

DeGruchy said he doesn’t know what the boys planned to do with the explosive materials and can’t say for sure where they learned the chemical recipe, but suspects it may be from the Internet.

The boys were all given summonses for criminal use of explosives, a charge that includes intent to use them, after the State Fire Marshall’s Office confirmed the potential danger of the chemical cocktail.