A Transportation Security Administration agent was shot and killed and another security agent was wounded Friday when a gunman opened fire at a security checkpoint at Los Angeles International Airport, NBC News is reporting.
Initial reports indicated that a gunman approached a document checker, then pulled a firearm and fired one shot at the security officer, according to NBC News' Pete Williams. Detective Gus Villanueva of the Los Angeles Police Department said police believe they have the gunman in custody.
Officers are sweeping through the terminal to make sure there are no other gunmen, said Villanueva.
Several travelers told NBC4 they heard gunfire in Tom Bradley Terminal. A medical triage area was established outside the terminal, but details regarding the conditions of the injured victims were not immediately available.
"We were just standing there and someone started shooting," witness Nick Pugh said. "I heard a total of maybe eight or 10 shots fired."
Pugh said he saw a man believe to be the gunman being chased by officers.
"He ran across the tarmac to get away and was put on ground and cuffed," Pugh said.
The shooting was reported at about 9:20 a.m. A camera positioned above the upper level road at LAX showed travelers running from the Tom Bradley Terminal, where passengers depart and arrive for international flights.
"People freaked out," said witness Tim Daly, who reported hearing 15 rounds. "No one knew what to do."
Officers escorted people -- some in wheelchairs -- from the terminal to the triage area. Several ambulances responded to the location on the departure level.
LAPD issued a tactical alert, meaning all personnel will remain on duty until the situation has been resolved.
Roads near the airport are closed for the investigation. Some travelers exited their vehicles and began walking to the airport with their luggage.
As incoming flights land, they are subject to a ground-stop order.
The shooting comes more than 10 years after a gunman walked up to a ticket counter for Israel's national airline, El Al, at LAX, killing two and wounding four in a July 4 terrorist attack.
President Barack Obama was briefed on the situation, according to authorities.