The two bombs that exploded at the Boston Marathon -- which killed three people and wounded 264 -- were detonated with the kind of remote device used to control a toy car, U.S. investigators told a House of Representatives panel on Wednesday, Reuters reports.

"It was a remote control for toy cars," U.S. Representative Dutch Ruppersberger, the top Democrat on the House Intelligence Committee, said after officials from the Department of Homeland Security, FBI and National Center for Counterterrorism briefed the committee. "Which says to me, and brother number two has said, they got the information on how to build the bomb from Inspire magazine." 

That magazine was created by Anwar al-Awlaki, an American-Yemeni preacher and a leader of al Qaeda's affiliate in Yemen who was killed in a U.S. drone strike, Reuters said.

Ruppersberger said the article on bomb-building in Inspire was headlined: "How to build a bomb in your mom's kitchen," according to Reuters.

Brothers Tamerlan and Dzhokhar Tsarnaev are suspected of detonating the two bombs, each housed in a pressure cooker, that exploded near the finish line of the Boston Marathon on April 15. Tamerlan, 26, was killed in a shootout with police, and Dzhokhar Tsarnaev, 19, who is in serious condition at a Boston hospital, has been proving authorities with some information, reports various new outlets.

Ruppersberger also said that some of the explosives used by the Tsarnaevs came from a fireworks shop in New Hampshire. "One of the brothers, the oldest brother, went to a shop in New Hampshire ... and asked for the most volatile explosives, so that you'd 'get the best bang,'" he said, according to Reuters.