A GUNMAN OPENED fire with an assault rifle at Los Angeles International Airport (LAX) last night, killing a security agent, creating scenes of chaos and causing widespread flight disruptions.

Panicked travelers scrambled to escape after the shooter, identified as 23-year-old Paul Anthony Ciancia, blasted through a security checkpoint at the airport.

Ciancia then walked calmly through the terminal seeking further victims, and was eventually stopped by police who shot and wounded him.

The dead agent was the first Transportation Security Administration (TSA) employee killed in the line of duty since the group was set up following the September 11, 2001 terrorist attacks.

The lone gunman, who reportedly had a grudge against the TSA, also wounded seven people in the firing rampage.

But he was still carrying plenty of ammunition when he was arrested, said Los Angeles Mayor Eric Garcetti.

“There were more than 100 more rounds that could have literally killed everybody in that terminal today,” he said, praising airport police. “If it were not for their actions, there could have been a lot more damage,” he said.

While reports suggested Ciancia — who was shot multiple times before he went down — was a disgruntled loner, the Federal Bureau of Investigation said it could not rule out terrorism.

The shooter opened fire shortly after 9:00 am in a crowded terminal of LAX, the country’s third-biggest air transport hub.

He “came into Terminal Three, pulled an assault rifle out of a bag and began to open fire,” said Patrick Gannon, head of the airport police.

YouTube: CNN

“He proceeded up into the screening area . . . and continued shooting,” he said.

Security camera footage that aired on TV showed people diving to the floor at the sound of gunfire and scrambling to escape the terminal.

Police chased the gunman to near a Burger King restaurant where they “engaged him in gunfire… and were able to successfully take him into custody.”

The TSA, which employs screeners and guards at airports, confirmed that one of its employees had died. “Multiple Transportation Security Officers (TSOs) were shot, one fatally,” said a TSA statement.

The FBI later named the shooter, and said that he was a Los Angeles resident who came originally from the eastern state of New Jersey.

Police found a note on the gunman voicing “disappointment in the government,” a law enforcement official told the Los Angeles Times newspaper, adding that family and friends indicated he could be suicidal.

It appeared that Ciancia targeted TSA agents exclusively. During the shooting spree, which lasted less than 10 minutes, he approached a number of people cowering in the terminal and pointed his gun at them, asking if there “were TSA.”

If they answered “no,” then he moved on, the Times reported, citing witnesses who said he cursed the TSA repeatedly.

In this photo provided to the AP, police officers stand near an unidentified weapon in Terminal 3 of LAX

Brian Adamick, 43, said he saw a wounded TSA worker, with a bloodied ankle, board a shuttle bus helping passengers escape.

"It looked like it was straight out of the movies," he said.

Some 750 flights were disrupted after the Federal Aviation Administration (FAA) issued a national ground-stop.

Although there was no indication that other people were involved in the attack, the FBI said it could not rule out terrorism.

"It would be premature to comment on a motivation at this time and joint investigators have neither ruled out terrorism, nor ruled it in," said an FBI statement.

In Washington, President Barack Obama was kept up to date on the shooting. "Obviously, we've been monitoring it and we're concerned about it," Obama said.

This being Los Angeles, a number of celebrities were caught up in the action.

Filming of an episode of the hit TV show "Mad Men" underway in nearby Terminal Four was halted, a crew member wrote on Twitter.

Actor James Franco posted a "selfie" picture of himself on a plane stopped on the tarmac by the incident.

"Some s** tbag shot up the place," he wrote in the first of a series of tweets, ending some five hours later with a more relieved message: "WE'RE OUT! - everyone was calm."

- © AFP 2013

LAX shooting: TSA agent killed, two injured, suspect in custody