Several people have been shot at a church in South Texas leaving multiple people dead and a number of other casualties, local media have reported.

As well as local police, the Federal Bureau of Investigation (FBI), the Bureau of Alcohol, Tobacco and Firearms (ATF) and US Marshals are all said to be on, or heading to the scene in Sutherland Springs about 40 miles east of San Antonio.

A sheriff says a man walked into the First Baptist Church in Sutherland Springs, Texas, and started shooting.

The Wilson County News reports that Wilson County Sheriff Joe Tackitt said the shooter dead. It wasn't immediately known how many people were killed and wounded or who carried out the attack.

Texas Governor Greg Abbott tweeted his condolences to those affected, calling it an "evil act".

A sheriff's department dispatcher says everyone is at the scene and unavailable to comment.

TeleKSAT reports that two Airlife helicopters are also at the scene.