A pro-gay US congresswoman shot in the head by a gunman is expected to survive.

Gabrielle Giffords, of Tucson, Arizona, was shot on Saturday as she held a meeting in a shopping centre.

Six people died in the attack, while another 13 were injured.

Ms Giffords is now said to be breathing on her own and has responded to doctors with hand signals.

Her doctors say she has a “101 per cent chance of survival”. Her husband Mark, a NASA astronaut, has been at her bedside.

Jared Loughner, 22, has been charged with the shootings.

He is accused of killing Ms Gifford’s aide Gabe Zimmerman, 30, US District Judge John Roll, Dorothy Morris, 76, Dorwan Stoddard, 76, Phyllis Schneck, 79, and Christina Taylor Green, nine, as well as injuring survivors.

Ms Giffords, 40, has been praised by gay groups for her commitment to equality.

The Congressional LGBT Equality Caucus said her support had “never faltered”, even when she was criticised for it.

“She has stood with us unrelentingly and in this sad time we stand with her. Our thoughts and prayers go out to the congresswoman, her staff and their families,” said LGBT Congressional Staff Association president, Chris Crowe.

The Human Rights Campaign said: “We are shocked and saddened by the events involving Congresswoman Giffords and our hearts go out to her and the other victims of this awful tragedy.

“Gabby Giffords is a champion for LGBT equality and a principled leader for Arizona. We wish her a speedy recovery as our thoughts and prayers are with her family as well as with the families of all of those touched by today’s horrific violence.”