Four US Marines, shooter killed in possible ‘domestic terrorism’ attack

A 24-year-old gunman opened fire at two US military centres in the southern state of Tennessee on Thursday, killing four Marines in what officials said was a possible act of "domestic terrorism". 

Others were injured during the incidents, but not seriously, reported the Wall Street Journal. A police officer was among those hurt, officials said.

The gunman, who was identified by the FBI as 24-year-old Mohammod Youssuf Abdulazeez, was shot dead. Three people were injured, including a police officer and a Marine Corps recruiter. 

The incident served as an ugly reminder of other deadly shootings at US military installations, including a 2009 rampage at Fort Hood that left 13 dead and a 2013 attack at the Navy Yard in Washington that left 12 dead.

President Barack Obama called the shootings "heartbreaking" and asked Americans to pray for the relatives of the victims.

"It is incomprehensible to see what happened and the way that individuals who proudly serve our country were treated," Chattanooga mayor Andy Berke said, praising the quick response by law enforcement to prevent further loss of life.

"Today is a nightmare for the city of Chattanooga."

The Wall Street Journal reported that investigators are now researching Abdulazeez’s life, to see if he might have had accomplices or if this was a sole act.

Bill Killian, the US federal prosecutor in that part of Tennessee, said the shootings were being investigated as an "act of domestic terrorism".

"We are looking at every possible avenue - whether it was terrorism, whether it was domestic, international or whether it was a simple criminal act," FBI special agent Ed Reinhold said.

The FBI said in a later statement that it was "premature to speculate on the motives of the shooter at this time," pledging to conduct a "thorough investigation of this tragedy."

Little was immediately known about the shooter.

NBC News and CNN reported that he was a naturalized US citizen, originally from Kuwait.

Local news network WRCB said Abdulazeez graduated from the University of Tennessee in 2012 with a degree in engineering.

A woman who attended Red Bank High School with Abdulazeez said he was a quiet kid, but well-liked.

"He was friendly, funny, kind," Kagan Wagner told the Chattanooga Times Free Press. "I never would have thought it would be him."

"They were your average Chattanooga family," Wagner said.

In an apparent blog post written Monday, Abdulazeez wrote Muslims should not let "the opportunity to submit to allah... pass you by," according to the SITE Intelligence Group, which monitors militant activity on social media.

Berke told CNN there had not been "any indication" that an attack was imminent.

The Marine Corps confirmed that all four victims were killed at a Navy and Marine Corps Reserve Centre in the late morning. About 40 minutes earlier, the gunman had opened fire at a recruitment centre several miles away.

Defense Secretary Ashton Carter and Navy Secretary Ray Mabus offered their condolences to the families of the victims.

“Though we can never fully prevent attacks like this, we will continue to investigate, review and guard against future vulnerabilities and do everything in our power to safeguard the security of our service members and their families," Mabus said in a statement.

The Department of Homeland Security said it had ordered security be stepped up at "certain federal facilities, out of an abundance of caution."

'All shook up'

Erica Wright said she witnessed the shooting at the recruiting centre through the window of a hair salon two doors down.

"We heard one pop, really loud pop. So we went to the door to see what it was," Wright told CNN. "We saw a guy in a silver Mustang just unloading on the naval recruiting place."

Wright said she watched in horror as the man reloaded his gun and opened fire again. He then backed up his car, pulled up to another part of the recruiting centre and started shooting again.

"We're all shook up," she said. "Never expected something like this."

Several locations in Chattanooga were placed on lockdown while the shootings were unfolding, including a local college, area businesses and government offices.

Bullet holes could be seen in the windows of the recruiting centre and shell casings littered the parking lot.

Senator Bob Corker, a former mayor of Chattanooga, said he was "heartbroken".

"This is a difficult day for Tennesseans and our thoughts and prayers are with all affected by this tragedy," he said in a statement.