A gunman wearing black tactical gear and wielding an AR-15-style rifle opened fire during Sunday services at a Baptist church in rural Texas killing 26 people. At least 20 others were wounded in the attack.

At a news conference on Sunday evening, Governor Greg Abbott verified the death toll, which climbed throughout the day as news of the shooting spread. It is the deadliest mass killing in Texas history.

Freeman Martin, the regional director of the Texas Department of Public Safety, told reporters that the gunman pulled up outside the First Baptist Church of Sutherland Springs at about 11:20 a.m. and started shooting. He then entered the church and continued his rampage.

According to Martin, a local resident grabbed a weapon and engaged the suspect as he left the church. The suspect then dropped his rifle, which Martin described as “a Ruger, AR-type,” and fled in his car. The civilian pursued the killer, who ran off the road a short time later and crashed. He was found fatally shot. Authorities said they did not know if he killed himself or was shot by the civilian.

Martin said 23 victims were found dead in the church, two were found outside the church, and another victim died on the way to the hospital. The church’s pastor, Frank Pomeroy, said his 14-year-old daughter, Annabelle, was among the dead. The victims ranged in age from 5 to 72.

Police would not confirm the gunman’s identity, saying only that he was a white man. Authorities also declined to identity of any of the victims. Martin said the motive is not yet known.

The First Baptist Church posts its services to YouTube, and its last sermon before today’s shooting, from October 29, shows how small the congregation is. Amanda Mosel, who said her 13-year-old goddaughter died in the shooting, said about 50 people usually attend services.

“It’s just a small church, that’s the other part of it that’s so sad,” Dana Fletcher, a local business owner, told CNN on Sunday afternoon. “It’s a little church in a very small community. I don’t know why it would be targeted.”

The town’s population is just 650, according to a local news outlet.

If initial casualty numbers hold, Sunday’s shooting, which comes just 35 days after a gunman in Las Vegas shot and killed 58 people and wounded hundreds more, is the fifth-deadliest in modern American history. It is also the deadliest church shooting ever recorded in the United States. In 2015, nine people were killed in a mass shooting at a historically black church in Charleston, South Carolina.