WASHINGTON – Fireworks stands in the nation’s capital are a reliable sign the Fourth of July is around the corner. But with suspected terrorists using fireworks to make bombs, sellers are being warned to keep their eyes open.

The Tsarnaev brothers, who bombed the Boston Marathon in April, fueled their devices with fireworks purchased across the border in New Hampshire, and USA Today reports that the National Explosives Task Force has asked fireworks retailers to look for suspicious activity.

The warning advises sellers to be alert to customers who ask how to take apart fireworks or ask about commercial-grade fireworks.

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