The main gate at Naval Air Station Pensacola is seen on Navy Boulevard in Pensacola, Florida, U.S. March 16, 2016. Picture…
FILE - The main gate at Naval Air Station Pensacola is seen on Navy Boulevard in Pensacola, Fla., March 16, 2016.

WASHINGTON - U.S. investigators are trying to determine what caused a Saudi air force pilot in the United States for flight training to go on a deadly shooting rampage at a U.S. naval base in Florida.

The shooting, which took place at the Pensacola Naval Air Station early Friday, left four people dead, including the shooter. A law enforcement official said another eight people were wounded.

Naval Air Station Pensacola

The U.S. Navy and law enforcement officials identified the shooter as a Saudi pilot, one of up to a few hundred foreign nationals who had come to the base in Pensacola for training.

NBC News, quoting law enforcement officials, further identified the shooter as Mohammed Saeed Alshamrani.

Late Friday, Fox News reported that the FBI has arrested six Saudi nationals in connection with the shooting.

Before the pilot opened fire at the base, he tweeted a will and quoted Osama bin Laden in justifying his actions, according to the SITE Intelligence Group, which translates jihadist threats and communications.

FILE- The entrance to the Naval Air Base Station in Pensacola, Fla.
Official: Base Shooter Watched Shooting Videos Before Attack
The official said 10 Saudi students were being held on the base Saturday while several others were unaccounted for

In the Twitter post, he said America “has turned into a nation of evil.” He condemned the U.S. for its support of Israel and its invasion of Muslim countries and many other countries. Using a bin Laden quote, he also said that the security of the U.S. and Muslims is a “shared destiny.” He added, “You will not be safe until we live it as reality in pleastain [sic], and American troops get our of lands.”

Guns are not permitted at the Pensacola Naval Air Station, but Escambia County Sheriff David Morgan said the shooter managed to get a handgun onto the base before targeting individuals at one of the buildings. Officials said the rampage ended when a sheriff's deputy cornered and shot the suspect in a classroom.

Officials with the U.S. FBI confirmed they were leading the probe, telling VOA it was still in the early stages.

"It is too early to determine motive," a FBI official said on condition of anonymity, admitting terrorism had not been ruled out.

This photo taken from video provided by WEAR-TV shows emergency responders near the Naval Air Base Station in Pensacola, Fla., Dec. 6, 2019.

Florida Governor Ron DeSantis said the nature of the investigation would be different because of the involvement of the Saudi air force pilot.

"There is obviously going to be a lot of questions about this individual being a foreign national, being a part of the Saudi air force," he told reporters.

"The government of Saudi Arabia needs to make things better for these victims," he added. "They are going to owe a debt here, given that this was one of their individuals."

U.S. President Donald Trump tweeted Friday that he had been in contact with King Salman, who offered condolences.

"The king said that the Saudi people are greatly angered by the barbaric actions of the shooter," Trump said.

Later, Trump told reporters at the White House, "It's a horrible thing that took place and we're getting to the bottom of it."

In a statement, Saudi King Salman called the shooting a "heinous crime" and said he expressed his sorrow over the attack in his phone call with President Trump. The king said he has directed Saudi security services to cooperate with American agencies to uncover information that will help determine the cause of the "horrific attack."

Hours after the shooting at the Pensacola Naval Air Station, a bomb threat at Patrick Air Force Base, also in Florida, forced authorities to evacuate parts of the base. Authorities later determined there was "no credible threat" and normal base operation resumed.

The shooting at the Pensacola Naval Air Station is the second deadly shooting at a U.S. naval facility this week.

A U.S. sailor shot three civilians at a base in Pearl Harbor, Hawaii, Wednesday, killing two of them before committing suicide.

In a response to both shootings, U.S. Defense Secretary Mark Esper said in a statement Friday, "The Department of Defense continues to monitor the situation in Pensacola and gather all the facts of each attack."

He said he is "considering several steps to ensure the security of our military installations and the safety of our service members and their families."    

Acting Navy Secretary Thomas Modly testifies during a hearing of the Senate Armed Services Committee, Dec. 3, 2019, in Washington.

"These acts are crimes against all of us," Acting Navy Secretary Thomas Modly said in a statement Friday.

"Our prayers are with the families of the fallen and with the wounded," he added. "It is our solemn duty to find the causes of such tragic loss and ceaselessly work together to prevent them."

"On behalf of all the U. S. servicemen and women serving around the world, I offer my deepest condolences and sympathies to the families of the victims of the shootings at the Pearl Harbor Naval Shipyard and Pensacola Naval Air Station," Chairman of the Joint Chiefs of Staff General Mark A. Milley said in a statement Saturday. We wish those injured in the attacks and their families the ability to find strength and healing as they recover. We are very thankful for the heroism and skill of local law enforcement and first responders, who diffused the situations and came to the aid of those at the scene."

Steve Herman contributed to this report.