A 60-year-old church usher has been hailed a hero after shielding other members of his congregation from a gunman who opened fire during a Sunday morning gathering in Tennessee.

The attack began as the 200-strong congregation were watching a youth performance of the musical Annie at the Tennessee Valley Unitarian Universalist Church in Knoxville on Sunday.

Church members dove under pews or ran from the building when the shooting started, but Greg McKendry stood in the front of the gunman and "took the blast to protect the rest of us”, one churchgoer said.

Mr McKendry perished at the scene, while Linda Kraeger, 61, died a few hours later at the University of Tennessee Medical Centre. Five people remained hospitalised, all in critical or serious condition, while two others were treated and released.

Church members said the gunman, Jim D. Adkisson, was tackled by John Bohstedt, who was playing Daddy Warbucks in the performance of Annie.

Mr Adkisson, 58, was charged with first-degree murder and held on $1 million bail.

The motive of Mr Adkisson, who was not recognised by witnesses, are a mystery, but one church member, Barbara Kemper, said she heard him say “hateful words”.

Another church member, Mark Harmon, was sitting in the first row and said the shooting began soon after the start of the performance of Annie, which featured 25 children.

“It had barely begun when there was an incredibly loud bang,” said Mr Harmon, whose wife told him that she saw the gunman pull the shotgun out of a guitar case. “It seems so unreal … You're sitting in church, you're watching a children's performance of a play and suddenly you hear a bang.”

According to its website, the Tennessee Valley Unitarian Universalist Church has, since the 1950s worked for desegregation, racial harmony, fair wages, women’s rights and gay rights.

Outside the church Reverend Chris Buice said: “We've been touched by a horrible act of violence. We are in a process of healing and we ask everyone for your prayers.”

The FBI was assisting in case the shooting turned out be a hate crime and police are taking statements from witnesses and collecting video cameras from church members who taped the performance.

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