The F.B.I. is investigating an early Thursday morning shooting at Naval Air Station Corpus Christi that injured a member of the Naval Security Forces and killed the shooter. Initial reports say the attack was "terrorism-related," but no further details have been released.

According to officials familiar with the case, the suspect was identified as Adam Alsahli. He was pronounced dead at the scene. Investigators are still searching for a potential second suspect. F.B.I. Supervisor Senior Resident Agent Leah Greeves refused to discuss the motive.

The shooting reportedly began around 6:15 AM on Thursday at the Corpus Christi base. Alsahli tried to advance through a gate in a vehicle. The base's security personnel put up a barrier to stop the car. The shooter got out of the car and began opening fire at the personnel. During the gunfire, the Navy's security personnel shot and killed the suspect.

Alsahli injured one Navy sailor during the shooting. The injured security personnel was taken to a nearby hospital. She was treated for minor injuries and was later discharged.

The base was placed on lockdown for five hours following concerns the suspect might have an explosive device. Navy experts found nothing after a sweep the area and the car. A second sweep of the crime scene led the security personnel to recover an unspecified electronic media.

The Navy lifted the lockdown before noon. The main gate was reopened, while the gate where the shooting occurred remained closed.

The F.B.I. is collaborating with the U.S. Justice Department's counterterrorism section and other federal and local officials to investigate all evidence uncovered from the scene as well as the circumstances that led to the event.

The Thursday shooting was the third time a suspect opened fire at a Naval base since December.

In December, a Saudi Air Force officer who was training at a Pensacola Naval facility shot and killed three American sailors and wounded eight others in what investigators deemed a terrorist attack.

A probe found that the gunman, Second Lieutenant Mohammed Saeed Alshamrani, had ties to the Al Qaeda for years. Federal authorities found evidence on the suspect's phone that showed the December attack was planned for years. They found footage of a classroom building and a written final will saved in Alshamrani's phone. The investigators also found a second, badly damaged phone they believe held essential data.

The American military expelled 21 other Saudi students from the training facility despite evidence Alshamrani was operating alone. Some of the former trainees were discovered to have links to extremist movements.

After the December shooting, the U.S. Defense Department banned all American installations from accepting and training international military students. In January, defense officials imposed stricter rules for international military students. Under the new orders, international trainees face restrictions on the use of firearms and access to government facilities. They would also be continuously monitored while they are enrolled in American training programs and facilities.

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