A gunman opened fire Thursday at Naval Air Station Corpus Christi, wounding at least one security force member in a "terrorism related" attack, authorities said.
The coastal base in Nueces County, Texas, about 140 miles southeast of San Antonio, was on lockdown after security responded to a report of an active shooter around 6:15 a.m.
The shooter was initially said to have been "neutralized," the base said in a Facebook post, before FBI agents confirmed that he had been fatally shot at the scene.
The injured security force member is in good condition and expected to survive.
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Several law enforcement sources identified the gunman to NBC News as Adam Alsahli, of Corpus Christi.
"We have determined that the incident this morning at the Naval Air Station in Corpus Christi is terrorism related," said FBI Senior Supervisory Special Agent Leah Greeves, who did not offer any further details.
"We may have a potential second related person of interest at large in the community," she said.
The base said earlier that the shooter was believed to be in the vicinity of its north gate.
"If you are in or near the North Gate get out and away to safety," a Facebook post read. "Execute lockdown procedures — remain indoors and away from windows."
All gates were closed while emergency responders assessed the scene.
The Naval Criminal Investigative Service, Houston's office of the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, and local law enforcement were offering assistance.