The shooting Thursday at a US Navy base in Texas in which one person was slightly wounded was a "terrorism-related" attack, an FBI spokesperson said.
The suspected shooter died, the FBI's Leah Graves said, without saying whether the person was killed or died of a self-inflicted wound.
Graves said that agents were looking for second person in connection with the investigation.
"We have determined that the incident this morning at the Naval Air Station Corpus Christi is terrorism-related," said Graves.
FBI agents are working with other law enforcement agencies on the probe, "which is fluid and evolving," Graves said.
The shooting occurred at approximately 6:15 am local time, the Houston office of the FBI tweeted.
"One sailor was injured. The sailor is in good condition and is expected to be released later today," the tweet read.
The FBI added that information about the suspect "will NOT be released at this time."
Fifi Kieschnick, a spokesperson for Naval Air Station Corpus Christi, where both US and foreign military personnel undergo flight training, earlier said that security forces had "neutralized" the shooter.
The incident comes five months after a Saudi air force student with al-Qaeda ties opened fire at a US Navy air base in Florida, killing three US sailors and injuring eight others.
On Monday US law enforcement officials said the Florida shooter had become radicalized at least five years ago and planned to undertake an attack before he arrived in the United States for military training.
Since then tougher rules have been set to prevent the thousands of foreign military trainees in the United States each year from accessing firearms, and to conduct more thorough background checks on them.