At least 26 people are dead after Devin Patrick Kelley wearing full combat gear walked into a Texas church and began shooting during a Sunday morning service.
There are reports of a "multiple casualties" - including a 2-year-old child - after a shooting at the First Baptist Church in Sutherland Springs, a small community south east of San Antonio.
Texas Governor Greg Abbott has confirmed 26 people have been killed with many more wounded.
Sheriff Joe Tackett confirmed there had been "multiple casualties and fatalities" inside the church, including children.
The shooter has been identified as a 26-year-old US Air Force veteran and Bible study teacher.
Kelley, of New Braunfels, a suburb of San Antonio, was killed after a brief foot chase into Guadalupe County, according Guadalupe County Sheriff's Office spokesman Robert Murphy. But it's still unclear if the gunman shot himself or was taken down by authorities.
San Antonio police raided Kelley's home on Sunday evening, with K9 and bomb squad units.
The wife of the pastor of the church says the couple's 14-year-old daughter Annabelle was among those killed.
Pastor lost his daughter
Sherri Pomeroy, wife of Pastor Frank Pomeroy, said she lost her daughter "and many friends" in the shooting.
She said both she and her husband were out of town and trying to get back to Sutherland Springs, outside of San Antonio.
Frank Pomeroy told ABC News by phone that Annabelle "was one very beautiful, special child".
A witness reported seeing a man dressed in combat gear walk into the First Baptist Church and begin shooting around 11.30am local time.
Local media said at least 15 people - including a 2-year-old - were injured.
Neighbours near the church said they heard the shooter reload "multiple" times while a service was being held. They say about 50 people usually attend services there.
At least six helicopters were called to the scene to take the injured to hospital.
Carrie Matula, who works at a gas station near the church, told MSNBC that she heard "semiautomatic gunfire" and looked to see what was going on.
"I never thought it would happen here," Matula said. "This is something that happens in a big city. I would never have thought this would have taken place here. It's just too tight a community. It doesn't make sense."
A woman who lives about 10 minutes away from Sutherland Springs in Floresville and was monitoring the chaos on a police scanner and in Facebook community groups, said that everyone knows everyone 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," she said.
The population of Sutherland Springs is said to be only about 400 people.
Texas Governor Greg Abbott said: "Our prayers are with all who were harmed by this evil act.
"Our thanks to law enforcement for their response."
The mass shooting comes just a month and five days after Stephen Paddock killed 58 people by opening fire on a concert in Las Vegas from his hotel room.