(CNN) -- Investigators have found no apparent ties between the Saudi Arabian military officer who killed three people at a US Navy base in Florida on Friday and terrorist groups, according to a senior administration official and a law enforcement source.

There have been some concerning statements and online materials discovered, but the investigation is still young, the administration official said.

Investigators gathering evidence from the mass shooting in which the gunman was killed by gunfire, and eight people were hurt are looking in several countries for answers into the shooter's motive and influences.

The FBI, which is leading the investigation, has not deemed the attack an act of terrorism, but that decision remains the subject of internal deliberations among agents in Florida and at FBI headquarters in Washington, a law enforcement source told CNN.

The source said numerous personnel and resources from the FBI's Joint Terrorism Task Force, criminal division, evidence response team, and FBI agents posted to Saudi Arabia continue to work jointly on the investigation.

Defense Secretary Mark Esper, who was at a defense forum Saturday said, "No, I can't say it's terrorism at this time. I think we need to let the investigators of the FBI do its work and tell us, get us the facts and we'll work out from there."

The gunman was vetted before his entry into a pilot training program and just after the shooting, and nothing of concern came up, sources told CNN.

The vetting is done against databases including known or suspected terrorists.

Killer was a second lieutenant

The shooter has been identified by the FBI as Mohammed Alshamrani.

Esper described him as a second lieutenant in the Saudi Arabian military involved in flight training. The shooter started his training in Pensacola in August 2017 as part of a three-year program. He was taking classes in basic aviation, initial pilot training and English, according to a spokesperson for the assistant to the Secretary of Defense.

In a report citing tweets attributed to Alshamrani, the US-based SITE intelligence group says Alshamrani quoted Osama bin Laden in a "will" posted to Twitter.

Additionally, SITE reported that postings show a hatred toward Americans for what he perceived as a pro-Israel stance.

CNN has not confirmed the Twitter account that SITE attributes to Alshamrani was his. Twitter told CNN the account referenced in the report was suspended but did not confirm it belonged to Alshamrani or the reason for the suspension.

According to a New York Times report, Alshamrani watched mass shooting videos at a dinner party the night before his attack. The newspaper says the information comes from a source briefed on the investigation but not authorized to speak publicly.

Alshamrani and a small group of Saudi nationals visited New York City over the Thanksgiving holiday, a law enforcement source told CNN. Alshamrani visited several museums and Rockefeller Center, where the tree lighting was taking place.

The source says the Saudi nationals that accompanied Alshamrami are currently being interviewed by law enforcement and are being cooperative. Authorities do not know the reason for their visit.

The New York Times first reported the details of the shooter's visit to New York City.

Other Saudis detained, source says

A number of Saudi nationals were detained after the shooting in which eight other people were injured at Naval Air Station Pensacola in Florida, a US official said Saturday. The US official did not provide information about the status of the Saudis who were questioned.

President Donald Trump said it is not known whether one person or a "number of people" were responsible.

"We will get to the bottom" of what happened, he said Saturday.

Shooting victim called a hero

Family members identified one of the victims as Joshua Kaleb Watson and praised him as a hero.

"After being shot multiple times he made it outside and told the first response team where the shooter was and those details were invaluable," Adam Watson wrote about his brother on Facebook. "He died a hero and we are beyond proud but there is a hole in our hearts that can never be filled."

Authorities have not released victims' names or discussed what victims told them at the scene.

Joshua Watson was from Enterprise, Alabama. In a statement obtained by CNN affiliate WDHN, Mayor Bill Cooper said, "The Enterprise community suffered a tremendous blow Friday upon hearing of the death of one of our own, Joshua Watson ... I am proud of him for his service and dedication to his country."

Shooter's uncle: 'Nothing suspicious'

Saad bin Hantim Alshamrani, an uncle of the shooting suspect, told CNN from Saudi Arabia that his nephew had done "nothing suspicious" before moving to the United States.

He said his nephew was 21 and "likable and mannered towards his family and the community." He added that his nephew "has his religion, his prayer, his honesty and commitments" and that he was a "likable kid, smart, he was exceptionally smart."

The elder Alshamrani said his country needs to "get to the truth" and that if his nephew was guilty, then he will be "accountable before God."

Foreign students have long trained at the base

Naval Air Station Pensacola employs more than 16,000 military and 7,400 civilian personnel, according to the base's website. Many families also live there, said retired Rear Adm. John Kirby, CNN military and diplomatic analyst, who was once stationed there.

Foreign students from "partner nations" have trained at the base to learn naval aviation for years, Commanding Officer of NAS Pensacola Capt. Tim Kinsella told reporters.

"There's always been international students training here because it's a good place to train, it's good quality training," he said. He roughly estimated that there were a couple hundred foreign students at the base.

At a news conference, Gov. Ron DeSantis mentioned the connection to the Saudi Air Force and said that he had spoken to Trump about it.

"There's obviously going to be a lot of questions about this individual being a foreign national, being a part of the Saudi Air Force and then to be here training on our soil," he said.

"Obviously," DeSantis added, "the government of Saudi Arabia needs to make things better for these victims."

Saudi King Salman expressed "deep sadness and sorrow" in the call, state-run SPA news reported. The king told the President that he ordered Saudi services to cooperate with the investigation, according to SPA.

Trump said on Twitter he has spoken with the King of Saudi Arabia about the shooting.

"The King said that the Saudi people are greatly angered by the barbaric actions of the shooter, and that this person in no way shape or form represents the feelings of the Saudi people who love the American people," the president said.

Asked whether the shooting would affect the US-Saudi military-to-military relationship, Esper said, "I don't see this undermining the deeper relationship we've had with the Kingdom of Saudi Arabia for decades."

Two deputies were wounded in confrontation

Authorities first received a call about an active shooter at NAS Pensacola around 6:51 a.m. Friday, Escambia County Sheriff David Morgan told reporters. The shooting occurred in a classroom building, Kinsella said.

The shooter used a handgun and was killed after two deputies exchanged gunfire with him. The deputies who confronted the shooter also suffered gunshot wounds -- one in the arm and one in the knee. Both are expected to survive.

The shooting came two days after an active duty US sailor, Seaman Gabriel Romero, killed two civilian employees and injured another before killing himself at Pearl Harbor Naval Shipyard in Hawaii. Investigators have not announced a motive for the Wednesday shooting.

The-CNN-Wire

™ & © 2019 Cable News Network, Inc., a WarnerMedia Company. All rights reserved.