A lone gunman walked into a church in a small Texas town yesterday and opened fire as the congregation worshipped - leaving as many as 27 dead and others injured.
The 14-year-old daughter of the church's pastor was one of a number of children killed.
The mass shooting occurred at the First Baptist Church in Sutherland Springs, about 50km from San Antonio, with witnesses saying the gunman started shooting at about 11.30am local time.
The gunman was later "taken down" by authorities after he fled the scene in his vehicle, according to Wilson County Sheriff Joe Tackitt, who said that at least 20 people had died. Local media said the death toll amounted to around half the congregation.
The exact number of dead was unclear, with estimates ranging from 20 to 28. Police official Albert Gamez Jr told CBS News 27 were killed.
"The details are kind of sketchy but what I know right now, what they're telling me, like 27 deceased and over 20, 25 injured," Mr Gomez Jr said. Other estimates put the number of injured at 10 to 15.
Church pastor Frank Pomeroy and his wife Sherri were out of town in two different states when the attack occurred.
"We lost our 14-year-old daughter today and many friends," Mrs Pomeroy said.
"Neither of us have made it back into town yet to personally see the devastation."
President Donald Trump tweeted his condolences from Japan where is undertaking a five-country trip of Asia.
Video on KSAT television showed first responders taking a stretcher from the church to a waiting AirLife helicopter.
Some victims were taken by medical helicopter to the Brooke Army Medical Center.
The church's website said its schedule was for a fellowship breakfast on Sunday mornings, followed by Sunday School.
A morning worship service was scheduled for 11am.
Megan Posey, a spokeswoman for Connally Memorial Medical Center, which is in Floresville and about 15km from the scene of the shooting, said "multiple" victims were being treated for gunshot wounds.
She declined to give a specific number but said it was less than a dozen.
A woman who lives about 10 minutes away from Sutherland Springs in Floresville, and who was monitoring the chaos on a police scanner and in Facebook community groups, said everyone knew each other in the sparsely populated county.
"This is horrific for our tiny little tight-knit town," said Alena Berlanga.
"Everybody's going to be affected and everybody knows someone who's affected."
Witnesses close to the small church reported hearing a rapid barrage of about 20 gunshots.
"It was very close," said Carrie Matula, who had been working in a store across the street from the scene. It was semi-automatic, rapid fire. This is just devastating in a small town like this."
Pastor Frank Buford, of the neighbouring River Oaks church, just a few blocks away from the scene of the shooting, said relatives of victims had started to congregate at a makeshift community centre where water and food was being brought.
"We're holding up as well as we can - we are a strong community, we are strong in our faith," he said.
Pastor Buford described Sutherland Springs as a close-knit community. The town has a population of around 600.
"We have a post office, two churches and a dollar store," he explained.
One law enforcement official said the gunman fled in a vehicle after the attack and was killed, though initially there was confusion as to whether he shot himself or was killed by police.
Federal law enforcement swarmed the area, including Alcohol, Tobacco and Firearms (ATF) investigators and members of the FBI's evidence collection team.
Friends and family of the victims gathered near the church waiting for words of what had happened to loved ones, tears flowing with many incredibly anxious.
"We're shocked. Shocked and dismayed," said state Senator Judith Zaffirini, a Laredo Democrat whose district includes Sutherland Springs. "It's especially shocking when it's such a small, serene area. These rural areas, they are so beautiful and so loving."
According to the Gun Violence Archive, which tracks gun violence, there have now been more than 300 mass shootings in the US this year.
The deadliest mass shooting in modern US history was just over a month ago in Las Vegas.
Fifty-eight people were killed and more than 500 injured by gunman Stephen Paddock.
Texas Governor Greg Abbott called the attack an "evil act".