And now, we held out west, to a mystery inside one of the nation's busiest air ports, l.A.X., Los angeles international. Who is planting small bombs made of dry ice? Abc's david wright on the new... See More
And now, we held out west, to a mystery inside one of the nation's busiest air ports, l.A.X., Los angeles international. Who is planting small bombs made of dry ice? Abc's david wright on the new clues around the airport tonight. Reporter: At the nation's third busiest airport, a mystery and a manhunt, for the person who has been busy this week, planting homemade bombs. In employee bathrooms at l.A.X. And even on the tarmac near jumbo jets. All four of these devices were found in restricted areas, parts of the airport where passengers aren't allowed to go. Three of them found here last night at the tom bradley international terminal. The other one found sunday. It explosions in terminal 2, all the way across the parking lot. Authorities have been quick to reassure the traveling public. No links to terrorism at this point. Reporter: They say the devices are dry ice bombs. Just put some water in there. Reporter: Youtube is full of fun. As the dry ice melts, the gas has nowhere to go. But they can be dangerous. California law treats them just the same as pipe bombs. Somebody will go to prison over this. Reporter: Today, the lapd and the fbi are reviewing security camera footage, looking for the culprit. In all likelihood, a disgruntled employee. Someone with access to restricted areas, and it would seem, a motive for mayhem. David wright, abc news, los angeles.
This transcript has been automatically generated and may not be 100% accurate.