Los Angeles International Airport police said Tuesday they were increasing security after a second dry ice bomb exploded and two others were found in a restricted area of the airport.
"The focus is definitely in the restricted area, not in the areas where passengers have access," said Sgt. Karla Ortiz. "We want to make sure that that get's tightened up."
Police officials say there appears to be "no nexus" between terrorism and the four bombs discovered over the last two days at LAX.
No one was injured in the explosions -- one Sunday night in an employee bathroom, one Monday night on the airfield near the planes. Two dry ice bombs that didn't explode also were found. The incidents are being investigated by the Los Angeles Police Department's criminal conspiracy division, Ortiz said.
The latest explosion occurred about 8:30 p.m. Monday near the gate area of the Tom Bradley International Terminal, law enforcement authorities said.
The devices -- bottles with dry ice inside -- appeared to be outside the terminal near planes where employees such as baggage handlers and others work on the aircraft and its cargo.
Airport officials will remind employees that "if you see something, say something," Ortiz said.
"We can't be everywhere all the time so we depend on them," she said.
was assisting the LAPD in the investigation into how the devices were placed in restricted areas at LAX.
There was minimal disruption of airport activities on Monday night, but the explosion on Sunday suspended operations in Terminal 2, and flights were delayed until about 8:45 p.m. as the LAPD bomb squad responded. Police estimated that about four flights were affected.
Passenger Feliciano Jiron told KCBS-TV on Monday before the second explosion that he was concerned that a dry ice bomb could be set at the airport, given all of LAX's security measures.
"Given the times we live in, it's a bit interesting that something like this would happen, even with all the security and all the efforts that people are putting forward," he said as he and his family arrived to catch a flight to New Mexico.