U.S. Northern Command (Northcom) has called for increased random security checks at all sites across Northern Command following the deadly shootings at Joint Base Pearl Harbor-Hickam in Hawaii and Naval Air Station (NAS) Pensacola in Florida.

The Navy on Saturday identified the three victims of the NAS Pensacola shooting as Ensign Joshua Kaleb Watson, 23, of Enterprise, Ala.; Airman Mohammed Sameh Haitham, 19, of St. Petersburg, Fla.; and Airman Apprentice Cameron Scott Walters, 21, of Richmond Hill, Ga.

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"The Sailors that lost their lives in the line of duty showed exceptional heroism and bravery in the face of evil," said the Navy chief of information in a statement. "When confronted, they didn't run from danger; they ran towards it and saved lives. If not for their actions, and the actions of the Naval Security Force that were the first responders on the scene, this incident could have been far worse."

"The Sailors that lost their lives in the line of duty showed exceptional heroism and bravery in the face of evil. When confronted, they didn't run from danger; they ran towards it and saved lives." — U.S. Navy statement

Meanwhile, the FBI on Friday night released its official photo of the Saudi gunman at NAS Pensacola, who has been identifed as Mohammed Alshamrani, a 21-year-old 2nd lieutenant in the Royal Saudi Air Force who was a student naval flight officer of Naval Aviation Schools Command.

Northcom said an advisory was sent out Friday night calling for the increase in security checks.

"Given the recent attacks at two military installations, the Commander, U.S. Northern Command has directed all DoD [Defense Department] installations, facilities and units within the U.S. Northern Command area of responsibility to immediately assess force protection measures and implement increased random security measures appropriate for their facilities,” Lt. Cmdr. Michael Hatfield told Fox News.

"The advisory also told leaders to remind their workforce to remain alert and if they see something, to say something by immediately reporting to appropriate authorities any suspicious activity they may observe," Hatfield said.

Northcom is one of the military's 11 combatant commands and provides military support for the continental U.S., Puerto Rico, Canada, Mexico and the Bahamas.

On Friday morning, a gunman identified as Alshamrani opened fire at NAS Pensacola, killing three.One of the victims, Watson, had been previously identified by his family.

The FBI asked anyone with information regarding Alshamrani and his activities to call 1-800-CALL-FBI.

FBI Jacksonville is not aware of any credible threat toward the Pensacola community at this time, its public affairs office said.

Six Saudi nationals were also detained for questioning regarding the incident.

The Saudi shooter wielded a handgun -- even though firearms are not permitted at the base -- before he was taken out by a pair of officers.

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Security was tightened at the base four or five years ago: the front gate is closed to civilians, and it would take them about 45 minutes to get through security. Not every car is always checked, but with increased random security checks more of them would be.

NAS Pensacola is home to the Naval Education and Training Security Assistance Field Activity's International Training Center, which the Navy says was “established in 1988 to meet the aviation-specific training needs of international officers and enlisted students from allied nations.”

The majority of the hundreds of foreign aviation students who have participated in the program are, like the gunman, from Saudi Arabia, the Navy said. Sources told Fox News that Alshamrani was “early” in his training.

Agence France-Presse reported that Alshamrani posted a short manifesto to Twitter before the shooting. The FBI told Fox News that it was aware of the anti-American Twitter post, but would not comment on whether it was looking into it as part of the investigation.

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A U.S. official said Saturday that the suspect also hosted a dinner party the week of the shooting where he and several others watched videos of mass shootings.

On Wednesday, Navy sailor Gabriel Antonio Romero opened fire at the Pearl Harbor Naval Shipyard in Hawaii. Romero fatally shot three civilians before turning the gun on himself.

Romero was an active-duty U.S. Navy petty officer who was just shy of his two-year anniversary with the Navy.