Horrifying footage shows the moment a gunman opens fire in a church in Texas, before being shot dead by a member of the congregation.
In the clip, taken during a service livestreamed on YouTube, the man kills a security officer at the West Freeway Church of Christ in White Settlement, near Fort Worth.
Several worshippers can be seen drawing weapons as the attack unfolds, with one firing the fatal shot which brings it to an end.
There are haunting screams after the killer fires his weapon, and dozens of people are seen diving under the pews.
He is immediately shot in front of the terrified worshippers, and died as a result of his injuries.
Officials at the church have said the killer was not known to them, describing the attack as "random".
One of the men died on their way to hospital.
The church was livestreaming its service on YouTube when the man began firing shots with a shotgun.
Worshippers ducked under their seats in fear as the gunman fired three shots.
Mike Tinius, a church elder, told the New York Times that a member of the place of worship's security team had been killed.
The attacker was shot dead by another security officer, he said.
"He was trying to do what he needed to do to protect the rest of us," Mr Tinius said.
"It’s extremely upsetting to see anyone committing violence."
Witness Isabel Arreola told CBS11 News : “It was the most scariest thing. You feel like your life is flashing before you.
"I was so worried about my little one."
She said the gunman walked up to a server during communion and opened fire with a shotgun.
Jeoff Williams, a regional director with the Texas Department of Public Safety, told reporters at a news conference. “I would like to point out that we have a couple of heroic parishioners who stopped short of just anything that you can even imagine, saved countless lives, and our hearts are going out to them and their families as well.”
Texas Governor Greg Abbott said in a statement: "Places of worship are meant to be sacred, and I am grateful for the church members who acted quickly to take down the shooter and help prevent further loss of life."
Texas Attorney General Ken Paxton said he was "shocked and saddened", CNN reports .
He stated: "As reports come in, please pray for any victims and their families, this congregation, and the law enforcement officials at the scene.
"My office will assist in any way needed."
The shooting happened around 10 miles west of Fort Worth.
Fort Worth Fire Department spokesman Mike Drivdahl said: "It’s a very tragic day.
"Our hearts and prayers go out to all the families that were affected by this incident."
