UPDATE: While the FBI is presuming the fatal shooting of three at a Pensacola, Florida, naval base on Friday was terrorism, they have yet to declare an official motive.

In a Sunday afternoon press conference, Rachel L. Rojas, FBI special agent in charge of the Jacksonville division, said federal, state, and local authorities are investigating the attack by suspect Mohammed Saeed Alshamrani, 21, a second lieutenant in the Royal Saudi Air Force who was in a training program at Naval Air Station Pensacola. He was killed by a sheriff’s deputy during the Friday morning attack.

The dead were identified by the U.S. Navy late Saturday as aviation students Ensign Joshua Kaleb Watson, 23, of Coffee, Alabama; Airman Mohammed Sameh Haitham, 19, of St. Petersburg, Florida; and Airmen Apprentice Cameron Scott Walters, 21, of Richmond Hill, Georgia.

The main goal of the investigation as it currently stands is to find out if Alshamrani acted alone or if he was part of a “larger network,” but authorities stressed Sunday that the community is safe and they do not suspect any other immediate or direct threats.

“This is our chance to get this right and I’m going to take my time,” Rojas said about the investigation.

Authorities are also working to discern if an ideology was a motivating factor in the attack, and are “working with the presumption that this was an act of terrorism,” Rojas said.

Agencies will continue to conduct interviews to learn more about the shooter.

Alshamrani had invited three Saudi flight students to dinner in the past week and showed them videos of mass shootings, but investigators believe they had nothing to do with the attack. Rojas said Sunday that no arrests have been made in the case.

“There are a number of Saudi students who were close to the shooter and continue to cooperate in this investigation,” Rojas said. All international students on the Pensacola base are currently accounted for, and Rojas thanked Saudi Arabian officials for their cooperation in this investigation. She added the Saudi commanding officer has “restricted” other Saudi students to their base.

Although non-citizens are normally prohibited from buying handguns, but since Alshamrani had a valid hunting license, he used a loophole to legally purchase his weapon from a dealer in Pensacola, law enforcement sources told NBC News on Saturday.

Lt. Col. Dave Eastburn, a Pentagon spokesman, said the suspect had been scheduled to complete a three-year U.S. Air Force Foreign Military Sales training program, funded by Saudi Arabia, in August.

Authorities believe a social media post critical of U.S. support for Israel and claiming America is anti-Islam belongs to Alshamrani. The post, which appeared before the shooting, is no longer live.

Law enforcement sources say investigators believe the shooter returned to Saudi Arabia after starting his U.S. training in 2017, and when he returned in February, he stopped socializing and going out as much with the three friends.

Eight people were injured in the attack, in addition to the three killed, including two local sheriff’s deputies who exchanged gunfire with the shooter.

PREVIOUS STORY: Three people were killed and multiple others injured, including two sheriff's deputies, in a shooting at a naval base in Pensacola, Florida, on Friday morning, officials said.

The shooter at Naval Air Station Pensacola was also killed, according to the Escambia County Sheriff's Office and the U.S. Navy.

Two Escambia County sheriff's deputies were on scene immediately after reports of a shooter at about 6:50 a.m. local time. They were injured in an exchange of gunfire with the shooter, authorities said.

One was shot in the arm and the other was shot in the leg and was in surgery, Chief Deputy Chip Simmons said during a morning news conference. They are both expected to survive.

"Walking through the crime scene was like being on the set of a movie," Sheriff David Morgan told reporters.

In addition to the two officers, five other people were injured, officials said. All seven had been taken to nearby Baptist Hospital for treatment.

The base was still on lockdown at about 10 a.m. and was to remain closed for the rest of the day, with only essential personnel allowed to enter. Pensacola Mayor Grover C. Robinson also asked residents to avoid the area around the base as investigators swarmed the scene.

The shooting unfolded in a two-floor classroom building at the base, which is a training facility.

Jeff Bergosh, a facilities manager at the base, had just arrived at the front gates when the station was put on lockdown, trapping thousands of workers in their cars.

“It’s been pretty surreal,” Bergosh told MSNBC. “We’re just praying for all the victims.”

He said more than 10,000 workers come to Naval Air Station Pensacola every day — many entering from Navy Boulevard, which Friday morning became a mileslong parking lot when the lockdown was ordered.

“When this happened was prime-time rush hour for all the base employees,” Bergosh said. “It was chaos with the ambulances and the police vehicles screaming by with the sirens. We knew pretty quickly that this was a pretty serious event.”

"Both gates of NASP are currently secured due to reports of an active shooter," a post said early Friday on the station's Facebook page.

President Donald Trump has been briefed on the shooting and is monitoring the situation, the White House said.

Vice President Mike Pence tweeted: "Saddened to hear of the horrible shooting at Naval Air Station Pensacola & continuing to monitor the situation. Praying for the victims & their families & we commend the first responders for their swift action in taking down the shooter & getting those on base to safety."

It is the second shooting at a U.S. military facility this week. On Wednesday, a U.S. sailor fatally shot two civilian Defense Department employees and wounded a third at the Pearl Harbor Naval Shipyard in Hawaii before killing himself, according to military officials.

The naval base incident Friday also comes one day after rumors of a shooting at a school in the same county, the Escambia County School District's Tate High School. The district office said the threats were not credible, but extra security was sent to the school.

Naval Air Station Pensacola employs more than 16,000 military and 7,400 civilian personnel. It was the nation's first naval air station and is the home of the popular Blue Angels flight demonstration squadron and the National Naval Aviation Museum, making it a popular tourist destination. It is also the headquarters of the Naval Education Training Command.

In 2016, the base was relatively late to enact security measures to separate the nearly 1 million tourists who visit each year from the sailors, Marines and other base employees, the Navy Times reported.

The naval air station established separate entrance gates for people who worked at the base and visitors, which are about three miles apart. Tourists also can't access military areas without passing through guard booths and roadblocks.