ABC News said the Department of Homeland Security and the FBI sent out a nationwide notice to law enforcement agencies reminding officers and agents a lot of fireworks are sold in July, and some could end up in the wrong hands.
"Recent incidents in the Homeland demonstrate that consumer fireworks -- widely used during the upcoming celebrations -- can be misused by criminals and violent extremists to construct improvised explosive devices," the notice said.
ABC said such notices are routine but the use of homemade bombs in an attack at the Boston Marathon in April may have added new urgency to the potential threat.
The FBI noted the accused Marathon bombers had allegedly considered carrying out their attack in Boston on July Fourth, in an area where a large number of people were present. The suspects allegedly obtained the gunpowder used in the bombs from a legal fireworks retailer in New Hampshire.