Security has been tightened at Los Angeles International Airport as officials scour surveillance footage for the culprit responsible for three dry ice bombs placed in secure areas of the airport, authorities said.
While experts say the devices are "inherently not as dangerous as other options," officials said they are concerned about the suspect's access to secure areas.
The Los Angeles Police Department and the FBI are working to track down the person or people responsible for planting the three devices in restricted areas of LAX in the last two days, said police, who are focusing on the possibility that it was a disgruntled employee and not an act of terror.
Two of the bombs exploded and one was discovered and disabled before it was detonated, police said. A fourth bottle the LAPD originally thought was involved turned out to trash and was not involved.
Deputy Chief Michael Downing told The Associated Press that the bombs, made by putting dry ice in 20-ounce bottles, could have caused serious injury to anyone in close proximity, though no one was hurt. Police are treating them as seriously as if they were pipe bombs.
The first explosion happened Sunday in a terminal men's bathroom and the second on Monday night near a gate, in an area accessible only to employees, police said. No one was injured, but they have put officials on high alert.
"There is no belief that there is a nexus to terrorism, but it's a big security issue," LAPD spokesman Lt. Andy Neiman told ABC News. "Obviously, somebody is doing something of concern at the airport. We're not sure who it is. ... It is someone who was able to get access to those [secure] areas of the airport."
Police are taking the devices and security breach seriously because dry ice bombs have the potential to be deadly, and if someone can get access to secure areas to plant the devices, authorities fear they could plant something far more dangerous or commit a more serious act.
"It's hard to get into the mind of a bomber, but if you're a bomber this is not the kind of device you would make if you want to kill people. There's much more lethal ways to put a device together," John Goodpaster told ABCNews.com.
Goodpaster is the director of the forensic sciences program at Indiana University-Purdue University's Department of Chemistry and Chemical Biology.
Los Angeles Airport Police said in a statement today that there are extra patrols at all terminals and in public areas.
"The safety and security of the travelling public is our priority and we want to reassure the public that LAX is safe," the statement said.
A law enforcement source told ABC News that investigators believe the person or persons responsible either work at the airport or have access to airport security credentials.
FBI spokeswoman Laura Eimiller told ABC News that investigators currently have "no indication of motive based on evidence."
Goodpaster said that while the devices can be dangerous, "They're generally regarded as not lethal ... This is just a pressure explosion."
"The danger for this kind of device would largely be if you were in direct contact with it. It's more the psychological impact," he said. "The person that's doing this is choosing a device that's inherently not as dangerous as other options."
Despite not necessarily being deadly, Goodpaster said under certain conditions dry ice can cause burns, small explosions and could even asphyxiate a person if they were to be in a room with dry ice and no other source of air.
The danger of the dry ice bombs depends on the amount of dry ice, the size of the container and the container's rigidity, Goodpaster said.
"The basic principal is that dry ice is solid carbon dioxide and then what it does is it sublimes, which is a process of turning into a gas," he said. "If you put it into something rigid, then inside of that container the gas builds up and then the pressure builds up until the container ruptures and then you get an explosion."
ABC News' Josh Margolin contributed to this report.