Tucson: A US congresswoman was in critical condition after a gunman opened fire at a public event, killing six people including a young girl and judge in an attack that shocked the nation.
Representative Gabrielle Giffords, a member of President Barack Obama`s Democratic Party, was meeting constituents at a suburban grocery store in Tucson, Arizona, when the assailant unleashed a volley of automatic fire.
Obama called the attack a "tragedy for our entire country”. The House of Representatives, which opened under new Republican leadership just three days earlier, called off proceedings for the upcoming week.
Bystanders tackled down the gunman, identified as 22-year-old local resident Jared Lee Loughner. News reports said he had filled the Internet with angry and largely incoherent condemnations of the government, while the Army said he had tried to enlist but was rejected.
"There`s some reason to believe that he came to this location with another individual," Sheriff Clarence Dupnik told reporters, saying the gunman "has kind of a troubled past, and we`re not convinced that he acted alone”.
Officials said six people were killed, including a nine-year-old girl and veteran federal judge John Roll, and 12 others were wounded.
Giffords was shot in the head but despite initial reports she had died, local television networks said she was awake in her hospital bed late Saturday and recognised her husband, NASA astronaut Mark Kelly.
"She is in critical condition (but) I`m optimistic about recovery," said University Medical Centre trauma chief Peter Rhee. "We cannot tell what kind of recovery, but I`m about as optimistic as you can get," he added.
At a later briefing however, Giffords family friend and former US surgeon general Richard Carmona was more cautious, saying: "With guarded optimism I hope that she will survive, but this is a very devastating wound."
Giffords was hosting an event dubbed "Congress on Your Corner" at a Safeway grocery store in a strip mall off a major intersection in Tucson, a city of rolling desert and cactus trees in the fast-growing southwestern state.
Giffords, like most rank-and-file US legislators, travelled without any security detail, according to witnesses
The incident came amid heightened security after packages ignited in a post office in Washington, DC on Friday and two government buildings in neighbouring Maryland on Thursday.
Sheriff Dupnik noted two incidents involving Giffords during the recent election campaign -- one when at a meeting "someone in the audience dropped a gun out of their pants," while in another windows were broken at her offices.
Denouncing "vitriol" notably by some media outlets, he added that a suspicious package had been found at her headquarters since the shooting, which was being investigated.
Giffords, the first Jewish woman to be elected to Congress from Arizona, barely survived a bruising re-election bid last year to a Republican rival from the right-wing Tea Party movement.
Giffords was a centrist and a member of the so-called Blue Dog Coalition of Democrats who support fiscally conservative, pro-business policies.
She has pushed for more troops to guard the nearby US-Mexico border and favoured a path to legalisation that would require illegal immigrants to pass a criminal background check, pay back taxes and learn English.
Obama condemned the attack as an "unspeakable tragedy" adding: "Such a senseless and terrible act of violence has no place in a free society."
Arizona Senator and former presidential candidate John McCain said: "Whoever did this; whatever their reason, they are a disgrace to Arizona, this country and the human race”.
While the United States has witnessed a stream of shootings, assassination bids against elected officials are rare. The last major incident was in 1981 when then president Ronald Reagan was shot and injured at a Washington hotel.
The only member of Congress ever to die in the line of duty was Leo Ryan, a California Democrat killed in 1978 in Guyana as he investigated a cult that later carried out a notorious mass suicide.
Other members of Congress were advised to review their security. The US Capitol police urged them to "take reasonable and prudent precautions regarding their personal safety and security”.
Former Arizona attorney general Terry Goddard said there had been previous threats against Roll ahead of the November 02 mid-term elections, in which the Republicans trounced Obama`s Democrats.
"There has been occasional violent talk this last election season," he said. "Violent talk sometimes begets violent actions."
Conservative standard-bearer Sarah Palin had controversially put Giffords on a political hit list, putting her under an image of a gun`s crosshairs for her support of Obama`s health care overhaul.
Palin offered condolences for the victims, writing on her Facebook page: "We all pray for the victims and their families, and for peace and justice."
Representative Eric Cantor, the leader of the new Republican majority in the House, announced that all proceedings would be postponed the following week "so that we can take whatever actions may be necessary in light of (Saturday`s) tragedy”.