A federal immigration agent shot and wounded a colleague at their office, before the gunman was killed by a third agent, the FBI says. Several shots were fired about 5:30 p.m. Thursday in the Immigration Customs Enforcement office, leaving one man wounded, said Steven Martinez, assistant director in charge of the FBI's Los Angeles office. Authorities released no details about what led to the initial shooting other than to say it was a case of workplace violence involving two federal agents. Streets are closed in downtown Long Beach surrounding the federal building on Ocean Boulevard after an ICE agent shot and injured another agent and was then killed by a third colleague in a federal building in Long Beach according to the FBI. FBI Special Agent Steven Martinez says the shooting occurred at about 5:30 p.m. (AP Photo/Brittany Murray, Long Beach Press Telegram) Close But the Los Angeles Times, citing multiple law enforcement sources, said the initial shots were fired by an agent at his supervisor during an unspecified dispute. The names of the dead gunman, the victim and the agent who fired the final rounds were not released. The wounded agent was hospitalized in stable condition, said ICE Special Agent in Charge Claude Arnold. St. Mary's Medical Center Trauma Director James Murray told KCAL-TV that the injured agent sustained wounds to multiple parts of his body, but did not further specify. He said the victim's vital signs were "good for now," and that he had ongoing bleeding but that it wasn't a cause for concern.