A Navy officer and a Marine fired their sidearms hoping to kill or subdue the gunman who murdered five service members last week returned fire on Muhammad Abdulazeez using a personal firearm during Thursday's mass shooting at the Navy Operational Support Center in Chattanooga, Tennessee, according to multiple military officials four Navy sources familiar with internal reporting on the tragedy.

It remains unclear whether the either hit Muhammad Abdulazeez, who was shot and killed on July 16 Thursday and after he gunned down four Marines and a sailor at the Navy Operational Support Center in Chattanooga. It's also unclear why they were armed, as it is against Defense Department policy for anyone other than military police or law enforcement to carry weapons on federal property.

A Sources tell Navy Times that a report was distributed among senior Navy leaders during the shooting's aftermath saying said Lt. Cmdr. Timothy White, the support center's commanding officer, used his personal firearm to engage Abdulazeez, Navy Times has confirmed with four separate sources released in the wake of the shooting that claimed the lives of four Marines and one sailor indicated that an officer assigned to NOSC Chattanooga engaged Abdulazeez, but it is unclear whether the officer hit the shooter or why the officer had a handgun in the building in the first place, since it is against Defense Department policy for anyone other than law enforcement to be armed. A Navy official also confirmed a Monday's Washington Post report indicating one of the slain Marines may have been carrying a 9mm Glock and possibly returned fire on the gunman.

This April 2015 booking photo released by the Hamilton County Sheriffs Office shows a man identified as Mohammad Youssduf Adbulazeer after being detained for a driving offense. A U.S. official speaking on condition of anonymity identified the gunman in shootings at two Chattanooga military facilities as Muhammad Youssef Abdulazeez, who shares the same age and address as the man in the photo. (Hamilton County Sheriffs Office via AP)
This April 2015 booking photo released by the Hamilton County Sheriffs Office shows a man identified as Mohammad Youssduf Adbulazeer after being detained for a driving offense. A U.S. official speaking on condition of anonymity identified the gunman in shootings at two Chattanooga military facilities as Muhammad Youssef Abdulazeez, who shares the same age and address as the man in the photo. (Hamilton County Sheriffs Office via AP)

The various law enforcement agencies investigating the Chattanooga shooting have Chattanooga police, the FBI, the Naval Criminal Investigative Service and the Chief of Navy Information all declined to comment, citing the ongoing investigation. A source close to the investigation said details of the rampage's last few minutes remain unclear, but that no information has emerged to in the days since the shooting has contradicted the Navy's internal findings reporting.

Authorities will not The source also said that law enforcement wouldn't know whether White or the Marine if the officer hit Abdulazeez until ballistics and an autopsy and ballistics assessment are performed report were done on the shooter.

Several attempts to contact White have proven were unsuccessful.

News of the Navy's internal reporting that a Navy officer fired on the gunman comes as other reports suggest amid confusing and contradictory reports that a Marine may have had been carrying a weapon and engaged Abdulazeez. On Tuesday, the Washington Post reported that the FBI recovered a 9mm Glock at the scene that may have been carried by one of the slain Marines and it may have been used to engage the shooter.

It is possible that both the Marine and the Navy officer were carrying personal firearms, but authorities the FBI and all agencies have steadfastly refused to comment on any of the details of their investigation beyond what's been they have public ally released publicly.

The shootings in Chattanooga unfolded on the morning of July 16 when, the FBI said says, Abdulazeez pumped dozens of rounds into a strip mall recruiting station before driving across town to the Navy support center in a strip mall across town from the NOSC but did not kill anyone inside. No one was killed inside the recruiting station. He then drove to the NOSC about 15 minutes away where he carried out an attack that killed five service members

Police responding to the first shooting at the recruiting station had to passed the Navy support center NOSC en route, and some were diverted to the scene of the second attack, according to a source with knowledge of the investigation.

According to FBI Special Agent in Charge Ed Reinhold, who spoke at a press conference July 22, Abdulazeez plowed his rented car through the gates, and with Chattanooga Police chasing close behind, the gunman got out of the car and stormed into the building. Abdulazeez wore a vest with extra ammunition and carried an assault rifle and a handgun. An additional gun was found in his vehicle.

A service member inside the building saw Abdulazeez approaching and fired at hit, Reinhold said. The investigator's description of this incident matches account of White's actions that day, as relayed by officials close to the investigation to Navy Times. The gunman shot back and then proceeded inside.

Once inside, he fatally wounded a sailor and "continued to shoot those he encountered," Reinhold said.

As police followed the gunshots, he then walked out the back door into a gated motor pool area, where troops tried to scramble over a fence to safety, and it was here that the four Marines were killed.

When the shooting first started, troops inside the building went room to room to rush their colleagues to safety, said Maj. Gen. Paul W. Brier, commanding general of the 4th Marine Division. Then, some rushed back into the fight.

Two guns belonging to service members were recovered at the scene, he said; shots were fired from at least one. It's unclear if the gunman was hit by one of those weapons, Reinhold said. The military will investigate whether the service members were authorized to have those weapons, he said.

NCIS head spokesperson Maryann Cummings would not say if this investigation would be led by her organization or the command, but said more information would be made available soon.

Killed in the attack were Marine Gunnery Sgt. Thomas Sullivan, Lance Cpl. Squire K. Wells, Staff Sgt. David Wyatt, and Sgt. Carson Holmquist. and Navy Logistics Specialist 2nd Class Randall Smith died early Saturday morning on July 18 from wounds sustained during the shooting.

The Associated Press contributed to this report.

In this aerial image taken from video, law enforcement personnel work the scene of a shooting at the Navy Operational Support Center and Marine Corps Reserve Center Chattanooga, Thursday, July 16, 2015, in Chattanooga, Tenn. Authorities say Kuwait-born Muhammad Youssef Abdulazeez, 24, of Hixson, Tenn., unleashed a barrage of gunfire from his car at a recruiting center and the U.S. military site, killing four Marines before he was shot to death by police. (WTVF via AP) MANDATORY CREDIT, NO SALES
In this aerial image taken from video, law enforcement personnel work the scene of a shooting at the Navy Operational Support Center and Marine Corps Reserve Center Chattanooga, Thursday, July 16, 2015, in Chattanooga, Tenn. Authorities say Kuwait-born Muhammad Youssef Abdulazeez, 24, of Hixson, Tenn., unleashed a barrage of gunfire from his car at a recruiting center and the U.S. military site, killing four Marines before he was shot to death by police. (WTVF via AP) MANDATORY CREDIT, NO SALES