Our thanks to law enforcement for their response. The shooter has been reportedly "taken down".
Neither the suspect's identity nor any possible motive were disclosed by authorities.
A witness told local news channel KENS5 that a child was among those who was shot.
Mr Silva said he had been approached by a woman who said she had two loved ones at the church who were shot.
At least 25 people are dead after a shooting at a Texas church on Sunday, US media reported.
Mrs Pomeroy said she and her husband were out of town at the time of the attack and were now trying to get back to Sutherland Springs.More news: Arsenal's Santi Cazorla could have lost foot after serious infection
The First Baptist Church is a fixture in Sutherland Springs, an area home to fewer than 900 residents, according the 2010 Census.
The governor also ordered all Texas flags lowered to half staff until Thursday to honor the lives lost in the shooting. Ted Cruz (R-TX) tweeted "keeping all harmed in Sutherland Springs in our prayers". "More details from DPS (Department of Public Safety) soon".
President Trump, who is in the midst of a 5-nation tour in Asia, said Sunday he is monitoring the incident from Japan.
The FBI has arrived to secure the scene.
While the exact casualty number is not known, a county commissioner, Albert Gomez, stated that as many as 27 were dead as a result of the mass shooting.
The shooting comes just over a month after a gunman in Las Vegas, firing down from a hotel room, killed 58 people and wounded hundreds attending an outdoor concert.
"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.