Devin Kelley: How the gunman massacred 26 at the Sutherland Springs First Baptist Church

He reportedly has been pictured on social media with an assault-style rifle

More than 20 are dead in Texas after a horrifying attack on a church (Getty Images)

At least 26 people have been killed and up to 20 more injured after a gunman entered a church and opened fire before fleeing the scene in a horrifying string of events.

The shooter, 26-year-old Devin Kelley, could be seen just moments before the violence at a nearby gas station roughly 20 minutes after the Sutherland Springs First Baptist Church had indicated online that morning prayer would begin. Kelley was later found dead in his vehicle, however it is unclear if his wound was self-inflicted.

Kelley was seen on security cameras at a gas station near the First Baptist Church in Sutherland Springs at 11:20 a.m., and reportedly crossed the street to begin his attack. He was dressed in all black at the time.

That 11:20 a.m. attack left more than two dozen dead, and many more injured. Some of the victims reportedly had multiple gunshot wounds. One of those with multiple gunshot wounds was a five-year-old boy.

Another one of the other victims, according to reports, was the 14-year-old daughter of the church pastor, who reportedly was not present Sunday for the service and had been traveling.

As Kelley exited the church, he was met by a nearby resident, who grabbed a firearm and engaged the suspected shooter. Kelley then dropped his rifle and fled the scene in his car.

Sutherland Springs is a small town in Texas just outside of San Antonio. The current death toll would represent roughly 7 per cent of the town’s population, which was reported at 362 people in the 2000 Census.

After fleeing the scene, the individual who had engaged him reportedly followed Kelley, who was said to have ben wearing tactical gear, and a ballistic vest.

He was later found dead in his vehicle near the border of Wilson and Guadalupe Counties, but it was not clear if he had died from a self-inflicted wound, or if he had been shot by the unidentified resident who pursued him.

Federal investigators are expected to provide assistance in the aftermath of the shooting. A spokesperson for the Texas Rangers in San Antonio did not confirm the name of the suspected killer, or the number of individuals who had been killed in the attack in the sleepy Texas town.

“You cannot put into words the pain and grief we all feel,” President Donald Trump, who is on an international trip to Asia, said of the attack. Mr Trump promised that federal resources would aide local Texan investigations in any way that they can.

Officials say they are looking at Kelley’s social media accounts, and that one previous photo shows him posing with an assault-style rifle.