Officials investigating the Boston Marathon bombings have said the explosives were detonated via remote, reports WCVB.
They also add that the transmitters were not "sophisticated" and required the bombers to hang around in the vicinity of where the bombs would explode.
This all comes a day after it was revealed that Tamerlan Tsarnaev — the older of the two suspected brothers, thought to be the mastermind — bought a massive amount of fireworks, so much so he got another set for free. A shop assistant at Phantom Fireworks in Seabrook, New Hampshire, says that in February Tamerlan came to the store and asked for the "biggest and loudest" firework set.
The store in New Hampshire is the same place that Faisal Shahzad, the failed Times Square bomber, also bought fireworks that he used to try to build a devastating bomb.