Fort Hood shooting: gunman takes own life after killing three and wounding 16
Iraq veteran suffering from mental health problems opened fire on colleagues before turning gun on himself
A US soldier shot dead three comrades before killing himself at the Fort Hood military base in Texas overnight, echoing a similar gun rampage at the same facility five years ago.
Ivan Lopez, a 34-year-old soldier suffering psychiatric issues after serving in Iraq, opened fire at the sprawling military base and wounded 16 people during the shooting spree, a senior US congressman said.
The killings took place at the same base where Nadal Hasan, a US army major who turned to radical Islam, killed 13 and wounded more than 30 in November 2009.
Michael McCaul, chair of the House homeland security committee, named the alleged shooter on CNN and said the killings appeared to be a "soldier-on-soldier" dispute rather than an act of terrorism.
President Barack Obama said he was "heartbroken" over the shooting which "re-opened the pain of what happened at Fort Hood five years ago".
The shooter used a .45 Smith & Wesson semi-automatic handgun that he had bought recently, rather than a military-issued weapon, said Lt General Mark Milley, Fort Hood's commander.
Lt Gen Milley declined to identify the gunman by name but said he was married and had served for four months in Iraq in 2011.
He had been "undergoing psychiatric treatment for depression and anxiety" and was being evaluated for post-traumatic stress disorder (PTSD), the general said.
The shooting spree was brought to an end when the gunman was confronted by a "heroic" female military police officer, he said.
"She pulled out her weapon, she engaged, he put the weapon to his head and died of a self-inflicted wound," Lt Gen Milley said.
"It was clearly heroic," he added. "She did her job, she did exactly what we would expect of a US military police officer."
The general said it was not clear what the killer's motives were but there was no immediate link to terrorism. "There is no indication that this incident is related to terrorism, although we are not ruling anything out," he said.
Officials at the nearby Scott & White Memorial Hospital said that patients' condition ranged from "stable to quite critical".
The shooting is believed to have begun at a medical building on the base, which stretches over 340 square miles and is one of the largest military outposts in the US.
As gunshots rang out, the base's thousands of troops, most of whom are unarmed, were ordered to take cover and lock doors and windows.
The base remained on lockdown for several hours on Wednesday evening before the all-clear was finally given, allowing soldiers and their families to return to their homes.
Speaking during a fundraising trip to Chicago, a solemn Mr Obama said: "Any shooting is troubling. Obviously this reopens the pain of what happened at Fort Hood five years ago. We know these families. We know their incredible service to our country and the sacrifices that they make."
He added: "We're heartbroken that something like this might have happened again."
The shooting comes nearly five years after Hasan, an army psychiatrist, shot dead 13 people and wounded another 32 in a shooting spree at Fort Hood.
Hasan joined the US military in 1988 but became increasingly radicalised after American forces invaded Afghanistan in response to the September 11th attacks.
In 2008, he began exchanging emails with Anwar al-Awlaki, an American-born al-Qaeda preacher known for trying to westerners to jihad. Al-Awlaki was killed in a US drone strike in Yemen in 2011.
Hasan opened fire on his fellow troops at Fort Hood on November 5, 2009 before being shot and wounded. He survived his injuries but was left paralysed from the waist down.
He admitted responsibility before a US military court and said he acted to protect the lives of Taliban fighters. In August last year he was sentenced to death for the shooting rampage.
Fort Hood is home to the US army's 1st cavalry division, one of the military's most decorated combat units.
Raf Sanchez, Telegraph.co.uk