Agent kills gun rampage colleague
An immigration agent opened fire on one of his colleagues before being shot dead by another official in a US government building.
FBI special agent Steven Martinez said the shooting happened at about 5.30pm local time on Thursday at the Glenn M Anderson federal building in Long Beach, California.
Mr Martinez said the shooting initially involved two federal agents. One fired several rounds at the other and wounded him, then another agent intervened, killing the shooter.
Immigration and Customs Enforcement (ICE) agent Claude Arnold said: "At times like this words honestly seem inadequate.
"When something like this happens in our offices, it's incomprehensible."
Names of the agents involved are not being released until next of kin have been notified.
In addition to ICE, the nine-story federal building also houses the Internal Revenue Service and the US Probation and Parole Office.