Exclusive photos of one undetonated bomb, obtained by ABC News, show the inside of the radio packed with tiny ball bearings and six magnets. Bomb experts say the magnets indicate the bomb was designed to be stuck to the side of a vehicle.
A surveillance photo of one of the alleged hit squad members, identified as an Iranian national named Saeid Moradi, shows him holding a radio in each hand.
According to authorities, a bomb exploded in the Bangkok house where Moradi and two other Iranians had been staying. After the blast, Moradi attempted to hail a cab. When the driver refused to pick him up, he allegedly threw a bomb, injuring four bystanders.
When police approached, Moradi allegedly threw another bomb, but lost both of his legs when it bounced back and exploded near him, according to Thai authorities. He was arrested following the incident and remains in custody in Thailand.
After the attack, police say they discovered two unexploded bombs in the house where Moradi and the other Iranians had been staying, including the one shown in the photos.
The authorities in Bangkok say they recovered more than a pound of white military explosive from one unexploded bomb that they said was to be detonated with an M26 hand grenade fuse. The photos show a pin that when pulled, authorities said, would trigger an explosion about four and a half seconds after it was pulled.
Israeli authorities and U.S. bomb experts say the bomb in the photos is strikingly similar to those used in other attacks last week in the republic of Georgia and India. "While there are small differences," said one U.S. expert, "they appear to be factory made."
Multiple authorities told ABC News the devices were either slipped through airport security or smuggled in a diplomatic pouch.
A magnetic bomb was discovered attached to the car of an Israeli diplomat in Tbilisi, Georgia and a similar device was believed responsible for the attack in New Delhi, which injured the wife of an Israeli diplomat, her driver and two passing motorists.
Iran has denied any connection with the arrests in Bangkok or to the other attacks.
Yoram Cohen, the head of Israeli's internal security service, Shin Bet, told an audience at a closed forum in Tel Aviv recently that Iran is trying to hit Israeli targets because of what it believes are Israeli attacks that have killed at least five scientists in its nuclear program.
What concerns authorities in the U.S. is that should Israel go to war with Iran, Israeli and Jewish targets in the U.S. could be hit by similar bombs in a terror campaign.