Live updates for this event have now concluded, but 1 NEWS NOW will continue to monitor the situation and provides updates in future stories.
Conneticut Senator Richard Blumenthal has called for congress to again push for stricter gun control laws in the wake of this latest shooting in Sutherland, just over a month on from the Las Vegas massacre.
Blumenthal, writing on Twitter, said Congress is complicit if they do not act now.
"Heartbroken for victims, loved ones, and all affected by the horrific tragedy in Sutherland Springs, Texas," he wrote.
"Horror, heartbreak, shame. Prayers are important but insufficient. After another unspeakable tragedy, Congress must act - or be complicit.
"Enough is enough. Now is the time for commonsense gun violence prevention steps. Congressional complicity must end."
Wilson County commissioner Albert Gamez Jr told CNN the shooter may have been shot and killed by Police after he tried to flee in a vehicle.
The shooter has not been identified as yet.
San Antonio Mayor Ron Nirenberg has issued a statement expressing his condolences.
"It's a sad day for South Texas," the statement reads.
"The investigation is ongoing and our community stads with Wilson County in prayer.
"To have such a violent act occur in a place of worship magnifies the pain for communities at large.
San Antonio holds our neighbors in prayer."
The shooting took place about 11.30am local time (6.30am NZT). KSAT reporter at the scene Erica Hernandez told ABC News that Sutherland is a "very, very small community" which will be shaken to its core by this shooting.
"For it to be this town ... it's something no one can fathom," she said, "this is going to be a big hit to this community ... this is not something you see every day here."
"we just got through reporting about Las Vegas."
Family members and residents of the town are now trying to verify with authorities whether their relatives are OK. CNN reports that the streets outside the church were lined with people looking for information.The entire church has been cordoned off and a local community centre has become a make-shift point where people can wait for information.
The BBC quotes a police commissioner at the scene as saying at least 27 people have been killed. The total number of people killed or injured has not been officially confirmed as yet, but it is also believed that a further 30 people are wounded.
A casualty count of 27 dead puts today's shooting on par with the Sandy Hook massacre, where 27 people were also killed. It is now the fourth-equal most deadly mass shooting in modern US history.
The five deadliest shootings up until today were:
Las Vegas shooting: October, 2017 - 58 dead
Stephen Paddock opened fire from a hotel window on concert goers, injuring about 500 and turned the gun on himself.
Pulse Nightclub shooting: June, 2016 – 49 dead
Omar Saddiqui Mateen opened fire inside the nightclub in Orlando, he was shot dead by police.
Virginia Tech shooting: April, 2007 – 32 dead
Seung-Hui Cho killed 32 people in two different locations. He then committed suicide.
Sandy Hook Elementary School shooting: December, 2012 - 27 dead
Adam Lanza shot dead 20 children and six adults, before killing himself.
Luby’s Cafeteria shooting: October, 1991 – 23 dead
George Hennard drove his truck through the Texas cafeteria and then shot at the patrons and committing suicide.
US President Donald Trump has reacted to the shooting on Twitter.
"May God be w/ the people of Sutherland Springs, Texas," he tweeted, "the FBI & law enforcement are on the scene ... I am monitoring the situation from Japan".
Texas Governor Greg Abbott described the shooting in a statement as a "horrific act".
"I want to thank law enforcement for their response and ask that all Texans pray for the Sutherland Springs community during this time of mourning and loss."
A County Commissioner in Texas says he's been told that more than 20 people were killed and more than 20 were wounded in an attack at a church, though he says those figures haven't been confirmed.
Albert Gamez, a Wilson County commissioner, made the comments to cable news outlets after the attack Sunday at a Baptist church in Sutherland Springs, a small community 30 miles southeast of San Antonio.
A sheriff says that a man walked into the church and started firing. Authorities say the attacker was later killed.
A man walked into a Baptist church in Sutherland Springs in Texas and started shooting, leaving multiple people dead, the sheriff said.
More than 20 were killed and 20 were wounded in the attack, a county official told broadcaster CNN, but the death toll is unconfirmed.
A heavy police presence was visible at the scene, and a cordon was in place.
The shooter was "taken down", Wilson County News reported the Wilson County Sheriff Joe Tackitt as saying.
First responders converged on the church in the small town southeast of San Antonio and helicopters were taking victims to hospitals.
Sutherland Springs is a community of about 400 people 48 kilometres southeast of San Antonio.