Police official Albert Gamez Jr confirmed the number of fatalities to CBS News.
The gunman, who is reported to have been killed in the aftermath, entered the church and opened fire at around 11:30 local time (17:30 GMT).
“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 Gamez Jr said.
“They’re talking about the shooter is dead also,” he added.
About 50 people usually attend the service, locals said. Local media outlets reported that children were among the dead.
Donald Trump, who is on a five-country tour in Asia, tweeted: “May God be w/ the people of Sutherland Springs, Texas. The FBI & law enforcement are on the scene. I am monitoring the situation from Japan.”
Witnesses close to the small church reported hearing a rapid barrage of about 20 shots. 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 center.
“We’re holding up as well as we can – we are a strong community, we are strong in our faith,” he told local reporters.
Buford described Sutherland Springs as a close-knit community. “We have a post office, two churches and a dollar store,” he said.
His church received word that a shooting was under way at their sister place of worship at about 11.15am local time, he said. “We started praying for everyone involved in it,” he said.
The pastor of First Baptist, Frank Pomeroy, and his wife were said to be out of town on Sunday and not present when the shooting happened.
First responders converged on the small town of around 400 people. Television stations KSAT and KENS reported a large police presence. A sheriff’s department dispatcher said everyone was at the scene and was unavailable to comment.
KSAT reported that two Airlife helicopters were at the scene and broadcast video of several fire and police vehicles at the church and a photograph of a helicopter that the station said was arriving to take victims to hospitals. PLACE YOUR TEXT ADVERT BELOW:>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> How I Made Me =N=2.5 MILLION In 7 Days from 2 Common Product I Imported and how you can do the same. Click HERE FOR FREE Details right now Warning To Men: This 3 Foods Is Killing Your Erection. Click Here To Know Them Secret Fruits that increased my Manhood and makes me last 55 minutes+ all time - Click here to get it Warning: Got Arthritis? 3 Simple Ways To Get Cured And Be Permanently Free From Joint Pains. Click Here To See Them REVEALED!! Reduce Your Blood Sugar Level And Reverse Diabetics Within A Short Period Of Time. Click Here To See How MIDNIGHT,Pressed Mr Kilanko Suddenly Couldn't Urinate. Shrink your Enlarged Prostrate Here! Click Here Now