UPDATE: Union official says TSA agent killed in shooting at Los Angeles airport

LOS ANGELES (AP) — A gunman armed with a semiautomatic rifle opened fire at the Los Angeles International Airport, killing a Transportation Security Administration employee and wounding two other people.

Tim Kauffman, a spokesman for the American Federation of Government Employees in Washington, confirmed today that a TSA officer was killed.

He says the union's information comes from their local officials in Los Angeles.

The attack frightened passengers and disrupted flights nationwide.

Police said the unidentified suspect, who was apparently injured following an exchange of gunfire with officers, was in custody.

Airport staff evacuated travelers and flights were disrupted nationwide.

Witness Brian Keech told The Associated Press he heard "about a dozen gunshots" from inside a security gate at the terminal, which has been evacuated.

The Federal Aviation Administration said a "ground stop" was in affect for all flights heading to Los Angeles, meaning planes in any other airport in the country can't take off for the city, although some flights already in the air were allowed to land.

LAX air traffic controller Michael Foote said some flights were still being allowed to depart.