“This has been a devastating week for our @USNavy family,” U.S. Chief of Naval Operations Michael Gilday wrote on Twitter. “Our hearts break for those who lost their lives in Pensacola and the wrenching pain it causes their loved ones. When tragedy hits, as it did today, and Wednesday in Pearl Harbor, it is felt by all.”

One of two sheriff’s deputies injured has been released from the hospital, while another is recovering after undergoing surgery, Escambia County Sheriff Major Andrew Hobbs said Saturday morning. Deputies arrived on the scene within three to four minutes, fatally shooting the gunman, he said.

Details on the condition of the six others injured were not immediately available.

The Federal Bureau of Investigation has taken the lead as authorities look into al-Shamrani’s past and motives. The FBI has not yet determined whether to classify the case as one of terrorism, though it is being reviewed, said a U.S. official, who spoke on condition of anonymity to discuss an ongoing investigation. An initial survey found no apparent connection to a foreign terrorist group, though the official cautioned that the investigation is still in its early stages. There are no indications of a conspiracy at the moment, the official said, adding that the shooter may have been self-radicalized.

Amid Florida leaders’ calls for heightened scrutiny of foreign nationals who come to the U.S. for military training, Secretary of Defense Mark Esper said he is “considering several steps to ensure the security of our military installations and the safety of our service members and their families” but did not explain further.

Some Florida leaders say the Saudi government should compensate victims. Saudi Arabia’s Ministry of Foreign Affairs on Friday expressed its “deep distress” over the shooting. President Trump said Saudi King Salman condemned the violence in discussions with him.

“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,” Trump tweeted.

Trump’s restraint stood in contrast to some of his past reactions to violence by people from predominantly Muslim countries.

Hours after eight people were killed in a 2017 alleged terrorist attack in New York City, Trump demanded officials “step up our already extreme vetting program. Being politically correct is fine, but not for this!” As a presidential candidate, the president once declared that “Islam hates us.”

Late Friday, several independent organizations published postings from a Twitter account said to belong to Shamrani, who officials say was a member of the Saudi air force and one of a couple hundred international students training at the Pensacola base. The postings, under the handle @M7MD_SHAMRANI, included a photo image of a letter in English apparently written a few hours before the shooting rampage. The Washington Post has not confirmed that the account belonged to the shooter.

Twitter suspended the account Friday afternoon.

Excerpts of the Twitter postings were published by SITE Intelligence Group and the Middle East Media Research Institute, two U.S. organizations that track extremist groups’ online propaganda.

In the letter, the writer blasts the United States for “funding crimes against Muslims” and supporting Israel. “You will not be safe until we live it as reality in [Palestine], and American troops get out of our land,” he writes.

The letter does not contain an explicit pledge of support for any group, but the contents echo views expressed by al-Qaeda as well as extremist clerics in the Persian Gulf, analysts said. The account profile lists the U.S. Chief of Naval Operations as among the accounts followed.

The posting, if authenticated, “suggests terrorist motive” and “echos Bin Laden,” SITE Director Rita Katz said in a Twitter posting.

“The style doesn’t necessarily resemble one group over another,” Katz said. “However, given that ISIS has very little to lose at this point, it wouldn’t be surprising if it claimed the attack, regardless of the attacker’s potential allegiances.”

Florida officials are already decrying the shooting as terrorism.

“Whether this individual was motivated by radical Islam or was simply mentally unstable, this was an act of terrorism,” said Sen. Rick Scott (R-Fla.), who urged a review of all programs that place foreigners with members of the U.S. military.

Republican House member Matt Gaetz, who represents Pensacola, also told reporters he believed the shooting to be a terrorist act rather than an “act of workplace violence,” though he did not detail his reasons.

The Defense Department operates a robust effort to train foreign military officers, with more than 5,000 such foreign students from 153 countries in the United States, officials said.

Those foreign nationals are vetted through a screening process that includes searching databases for evidence of drug trafficking, support for terrorist activity, corruption and criminal conduct, officials said.

Pentagon officials said Shamrani’s training with the U.S. military began in August 2016, and was scheduled to finish in August 2020. His coursework included English, basic aviation and initial aviation training, officials said.

It was not immediately clear whether the three deceased victims were service members or civilians.

Baptist Health Care said it had admitted eight patients from the shooting but could not yet report on their conditions. “Our teams are treating patients and we are working with Navy personnel to communicate with family members,” the hospital said in a statement.

The first reports of a shooting inside an air station classroom came in at 6:51 a.m., when law enforcement officers began rushing toward the incident while Navy officials placed the base on lockdown. After about an hour, authorities said the gunman was dead.

“There was some real heroism today,” said the base’s commanding officer, Capt. Timothy F. Kinsella. “I am devastated, we are in shock, this is surreal, but I couldn’t be prouder to wear the uniform that I wear because of my brothers and sisters in uniform, civilian or otherwise, that did what they did today to save lives.”

The base said it would be open only to “mission essential personnel” and residents through the weekend. A family assistance center opened Friday and continued to provide support Saturday, offering counselors to those affected.

The FBI investigation is being aided by military investigators, the Bureau of Alcohol, Tobacco, Firearms and Explosives, and local police.

Escambia County Sheriff David Morgan warned that because of the nature of an attack on a military base by a foreign national, investigators would not be able to reveal everything they learn about the case.

“Do not expect quick answers,” the sheriff said. “There’s going to be some parts of this investigation . . . that you may never have access to, just because of . . . who we’re dealing with. That will be extremely frustrating for you.”

The sheriff noted that in two weeks’ time, most people will not remember the names of anyone killed or wounded in the attack, but their families will be marked by the tragedy for the rest of their lives.

“You’re going to have to trust us. We’re going to tell you what you need to know to keep our communities and our state and our nation safe,” he said. “You will hear the truth from us, as best we can tell you.”

Civilian and military investigators spent Friday afternoon poring over the gunman’s military history and other records, including social media, for clues about what might have motivated him.

Friday’s incident shook a community whose identity is deeply entwined with the base, with many residents either employed there or tied to related businesses that sprawl alongside Pensacola Bay.

Jana Lormer, who is renovating her grandmother’s home directly across the bayou from the base, comes from a long line of service members — like many in the neighborhood. She said the area’s usual sense of quiet had been shattered.

“I woke up and opened my texts to all of these messages and then looked across the water to see all the ambulances on the bridge,” she said. “It was too close for comfort.”

The facility hosts 16,000 military personnel and more than 7,000 civilians

“For 200 years, they have been a part of the city of Pensacola,” Mayor Grover C. Robinson IV said during a news conference. “We’re a military town.”

The shooting could put additional strain on the U.S.-Saudi relationship, which has been tested recently by legal and diplomatic troubles.

Last month, the Justice Department charged two former Twitter employees with spying for Saudi Arabia by accessing information about Saudi dissidents who used the social media platform, marking the first time federal prosecutors have publicly accused the kingdom of running agents in the United States.

One of those implicated in the scheme, according to court papers, is an associate of Saudi Crown Prince Mohammed bin Salman, who the CIA has concluded likely ordered the killing of the journalist Jamal Khashoggi in Istanbul last year. Khashoggi was a Washington Post contributing columnist who advocated for free expression in the Arab world.

In September, the U.S. Justice Department decided to provide families of the victims of the 9/11 attacks some information that the FBI learned about Saudi government activity related to those attacks; 15 of the 19 plane hijackers were Saudis.

Friday’s shooting in Florida came just two days after a gunman opened fire at Joint Base Pearl Harbor-Hickam near Honolulu, killing two base workers identified by authorities as Vincent J. Kapoi, a metals inspector apprentice, and Roldan A. Agustin, a shop planner.

The shooter in that incident was identified as an active-duty U.S. Navy sailor and his three victims as civilian Defense Department employees working at the base’s shipyard, but officials do not suspect terrorism was the motive in that case.

The gunman, Gabriel Romero, was assigned to the USS Columbia, a submarine undergoing maintenance at Dry Dock 2, where the shooting occurred, officials said.

After that incident, military officials said Romero had been receiving counseling and was unhappy with his commanders. He was also involved in a low-level administrative process for minor misconduct, officials said.