A U.S. official says the gunman in the shootings in Tennessee has been identified as 24-year-old Muhammad Youssef Abdulazeez.
He was believed to have been born in Kuwait, and it was unclear whether he was a U.S. or Kuwaiti citizen. The official was speaking on condition of anonymity to discuss the ongoing, sensitive investigation. It was not immediately clear whether the gunman's first name was spelled Muhammad or Mohammad.
He is from Hixson, Tennessee, which is just a few miles across the river from Chattanooga.
Authorities and officials say the gunman killed four Marines and wounded a police officer and others in two attacks on military facilities. The gunman was also dead.
The Chattanooga mayor says the killings of four military personnel during an attack on two facilities in the city are "incomprehensible."
Mayor Andy Berke said at a news conference Thursday that the shooter had also been slain. He didn't say how. A police officer and others were also wounded in the attacks.
"I want to say again, it is incomprehensible to see what happened and the way that individuals who proudly serve our country were treated," he said. "As a city, we will respond to this with every available resource we have."
A U.S. attorney says the killing of four people during a shooting rampage in Chattanooga is an "act of domestic terrorism."
U.S. Attorney Bill Killian made the comments Thursday during a news conference. Mayor Andy Berke says two different military sites were "viciously attacked." The shooter was killed at a Naval reserve center, where the victims were also slain.
There was also a shooting at a military recruitment center about 7 miles away.
The death toll in the Chattanooga shootings includes four U.S. Marines and the sole gunman believed responsible, a U.S. official told The Associated Press, speaking on condition of anonymity to discuss an ongoing investigation.
The official said two others, a soldier and a police officer, were wounded.
The shootings happened at two military facilities in Chattanooga on Thursday, sending troops scrambling for safety.
Associated Press writer Ted Bridis in Washington contributed to this report.
Tennessee Gov. Bill Haslam says people serving their country have lost their lives in the attacks on two military facilities there.
Haslam did not say how many people were killed or provide further details about who was among the dead on Thursday.
Chattanooga police say the active shooting is over, but they have not said what happened to the suspect or suspects.
Mayor Andy Berke said earlier at a news conference that there was "an officer down" at a military reserve center.
An active duty Army recruiter in Chattanooga says he was at his office when someone opened fire and he heard 30 to 50 shots.
Sgt. 1st Class Robert Dodge, 36, was working at the Armed Forces Career Center off Lee Highway. There are also offices for Air Force, Navy and Marine Corp there.
"We heard one single shot, which kind of sparked our attention. Shortly after that, just a few seconds, the shooter began shooting more rounds. We realized it was an actual shooting, so we then initiated our active shooter drill: getting down low to the ground, moving to a safe location. And we waited until everything seemed to be clear."
He said he did not see the shooter or a vehicle.
Chattanooga police say the active shooting is over, but they have not said what happened to the shooter.
President Barack Obama has been briefed by his national security team on the shooting involving two military sites in Tennessee.
White House spokesman Eric Schultz says that the president will continue getting updates from his staff as needed.
Chattanooga police say the active shooter situation is over, but they have not said what happened to the suspect or suspects.
Obama was in Oklahoma to speak about criminal justice reform at a federal prison at the time of the shooting. He plans to return to Washington on Thursday afternoon.
Shootings have been reported at two locations in Chattanooga.
One of them took place at the Armed Forces Career Center off Lee Highway. Television images of a door to the center in a strip mall showed more than a dozen bullet holes in the glass.
About 7 miles away, another shooting happened at the Navy Operational Support Center and Marine Corps Reserve Center.
That center sits between the highway and a pathway that runs through Tennessee RiverPark, a popular park at a bend in the Tennessee River northeast of downtown Chattanooga. It's in a light industrial area that includes a Coca-Cola bottling plant and Binswanger Glass.
The two entrances to the fenced facility have unmanned gates and concrete barriers that require approaching cars to slow down to drive around them.
Police say the active shooting situation is over, but there is no word what happened to the suspect or suspects.
Chattanooga police say the active shooting that apparently took place at two military facilities is now over, but there is no word yet on what happened to the suspect or suspects.
Police said in a tweet: "Active shooter situation is over. Details forthcoming."
Chattanooga Mayor Andy Berke said earlier at a news conference that it was a "very terrible situation." He did not release any other details. Berke said there's "an officer down" at a military reserve center.
It was not immediately clear how many people may have been hurt, or how many shooters may have been involved.
A woman who says she witnessed the shooting in Chattanooga says she heard a barrage of gunfire near one of the shooting sites.
"It was rapid fire, like pow pow pow pow, so quickly. The next thing I knew there were police cars coming from every direction," said Marilyn Hutcheson, who works at a Binswanger Glass.
Chattanooga Mayor Andy Berke said at a brief news conference that police were pursuing an active shooter and there was an officer down.
Hutcheson says she ran inside, where she remains with other employees and a customer. The gunfire continued with occasional bursts she estimated for 20 minutes.
"We're apprehensive," Hutcheson said. "Not knowing what transpired, if it was a grievance or terroristic related, we just don't know."