An airport security agent has been killed and seven other people have been injured in a shooting that prompted evacuations at Los Angeles International Airport.
Airport officials have confirmed the arrest of a suspect, who was shot in the chest before being taken into custody.
Police say the man was carrying a high-powered rifle.
Media reports say the man opened fire on a Government Transportation Security Administration agent.
Airport police say the attack was the work of a lone shooter, who pulled an assault rifle out of a bag and began shooting in the terminal. Ten shots were fired.
It is understood the man arrested was carrying a handwritten note promising to kill members of the Transportation Security Administration and police, the BBC reports.
All flights leaving the airport were cancelled, and police and aviation officials also stopped some planes landing.
Eyewitness Chuck Turrett says people began running after an initial burst of gunfire.
"It just sounded like somebody was banging on something but there was a stampede of people coming my way and I realised that something was very wrong, and people were panicking," he says.
Fleeing passenger Sarah Richardson says the attack happened in an area where passenger identities were being checked before a security point.
"It was pretty jarring that someone just randomly pulled a gun right in the middle of nowhere," she says.
United States President Barack Obama has been briefed on the incident and the White House is in touch with law enforcement officials on the ground.
NZ flights affected
The shooting caused chaos at one of the world's biggest transport hubs and is still disrupting the travel plans of thousands of passengers.
Air New Zealand says a flight from Auckland landed at the airport but has been waiting on the tarmac with 356 passengers on board.
It says the Federal Aviation Administration has ordered a stop to all flights arriving in Los Angeles that have not yet left their destination.
Two Air New Zealand flights from Auckland and London are due to land later on Saturday and are already en route.