KILLEEN, Texas -- At least four people were killed and 14 injured in a shooting at Fort Hood, according to a senior defense official. Fort Hood says it cannot confirm those numbers, but that several patients have been rushed to area hospitals.
CNN and CBS are reporting the dead include the shooter who died from a self-inflicted gunshot wound.
Sources told CBS News the shooter had been identified as 34-year-old soldier Ivan Lopez. A source said the violence apparently stemmed from some sort of soldier dispute.
A Fort Hood official said Lopez was being assessed for whether he had PTSD.
Lt. Gen. Mark A. Milley said the wounded were all military members.
Milley said there is no indication the shooting was related to terrorism and that he is married and served in Iraq in 2011.
Six of the injured victims were taken to Baylor Scott & White hospital in Temple, a level one trauma center. Their conditions range from "stable to quite critical" doctors said in a news conference.
Sirens signalling all-clear sounded on Fort Hood and the lockdown was lifted just before 9 p.m.
Witnesses said the first shots were fired around 4:25 p.m.
"So everyone was kind of like 'what the heck? Is that a car backfiring?," said a soldier on the base who didn't want to give his name. "And immediately after it was followed by another burst and it was kind of like, 'Oh OK something is happening, something is going on.'"
Then they saw several soldiers sprinting across a parking lot and jumping a fence.
"And the fence is about 7-and-a-half to 8 feet high and it's lined with barbed wire at the top, and so therefore we knew, OK if they're willing to jump over a barbed wire fence and sprinting, something is wrong. And that's when everybody was sent on lockdown and sent to rooms," he said.
"All personnel on post are asked to shelter in place," according to a statement on the official Twitter feed of the Central Texas army base.
The 1st Cavalry Division, which is based at Fort Hood, sent a Twitter alert telling people on base to close doors and stay away from windows.
The witness said they heard another round of shots fired around 5:15 p.m.
Meanwhile, relatives of soldiers waited for news about their loved ones.
Tayra DeHart, 33, said she had last heard from her husband, a soldier at the post, that he was safe, but that was hours earlier.
"The last two hours have been the most nerve-wracking I've ever felt. I know God is here protecting me and all the soldiers, but I have my phone in my hand just hoping it will ring and it will be my husband," DeHart said.
Brooke Conover, whose husband was on base at the time of the shooting, said she found out about it while checking Facebook. She said she called her husband, Staff Sgt. Sean Conover, immediately to make sure he was OK, but he couldn't even tell her exactly what was going on, only that the base was locked down.
"I'm still hearing conflicting stories about what happened and where the shooting was exactly," Conover said in a telephone interview, explaining that she still doesn't know how close the incident was to her husband.
"I just want him to come home," said Conover, who moved to Fort Hood with her husband and three daughters two years ago.
Central Texas College in Killeen was evacuated and Wednesday night classes were cancelled as a precaution.
Ford Hood near Killeen was the site of a mass murder on Nov. 5, 2009, when Maj. Nidal Malik Hasan, an Army psychiatrist, opened fire at a soldier readiness center on the base. He shot 13 people dead and wounded more than 30 others. It was the worst shooting ever to take place on an American military base.
Hasan has been sentenced to death for the rampage.