Arizona Rep. Gabrielle Giffords was fatally shot in the head at close range by a gunman Saturday morning outside a grocery store in Tucson while holding a public event, Fox News has confirmed.
Eight others were shot, including three of the Arizona Democrat's aides, at Giffords' ""Your Corner"" event held at a Safeway grocery story. A suspect is in custody.
The three staffers who were shot worked out of Giffords' Arizona office.
Giffords has held multiple ""Your Corner"" events over the past four years, the aide told Fox News, adding that she had held three previous events that this venue before.
In November, Giffords was re-elected to her third term as representative of Arizona's 8th Congressional District. She is married to astronaut Mark Kelly.
US Democratic congresswoman Gabrielle Giffords has been shot in the head during an event in Tucson, Arizona and is in a critical condition in hospital.
Earlier there had been reports she died as a result of her injuries but a spokeswoman for University Medical Centre said: "She is currently in surgery. She is alive."
Nine other shooting victims are also being treated at the hospital with serious injuries.
The gunman was reportedly shot and is now in police custody.
The congresswoman was holding an event called 'Congress on Your Corner' outside a supermarket and had earlier tweeted for her constituents to attend.
She was shot at point blank range in the head and airlifted to hospital.
Eyewitness Andrea Gooden told Fox News: "I heard about 15 shots consecutively and quickly after that there were people racing across the parking lot to the nearby store.
"I was working across the street...there was an immediate response and within a minute the sheriff and firefighters were on the scene."
Mrs Giffords was re-elected to the House of Representatives in the US elections in November, focusing on immigration reform, military issues, stem call research and alternative energy.
The 40-year-old is married to NASA shuttle commander Mark Kelly who commanded the final scheduled shuttle flight in April.
Sky's Greg Milam said: "What is not clear at the moment is how many other people have been shot.
"There are conflicting reports that 12 or 15 others were shot.
"There are questions about who could be behind this and what motivation anyone could have had."