Security agent killed at Los Angeles airport

A man has opened fire with an assault rifle in a crowded terminal at the Los Angeles International Airport in the United States, killing a security agent and wounding at least six other people before he was shot and captured, authorities say.

The Transportation Security Administration (TSA) said three of its staff had been injured, one fatally.

The suspect - named by the FBI as 23-year-old Los Angeles resident Paul Anthony Ciancia - was wounded by police and detained.

The gunfire in Terminal 3 touched off panic and chaos at one of the world's busiest airports as passengers fled or dove for cover behind racks of luggage and police shouted warnings to travellers and quickly evacuated the terminal.

The shooting occurred around 9:30am local time (16:30 GMT) on Friday.

Departing flights were halted and arriving planes were diverted to other airports, as streets surrounding the airport were shut down, causing traffic jams for several kilometres.

"An individual came into Terminal 3 of this airport, pulled an assault rifle out of a bag and began to open fire in the terminal," Patrick Gannon, chief of the Los Angeles Airport Police, told a news conference.

Gannon said the gunman, who appeared to be acting alone, made his way past the screening gates and into a food court area located "very far into the terminal", where law enforcement officers tracked him down, shot him at least once and took him into custody. He was taken to a local hospital and was said to be in critical condition.

The airport terminal was evacuated in the immediate aftermath of the shooting, with flight operations severely disrupted.