Six people were killed and a US congresswoman was in critical condition after being shot in the head Saturday by a gunman who opened fire at a public event in Tucson, Arizona, medics said.
The Democratic lawmaker Gabrielle Giffords had been hosting a "Congress on Your Corner" event with constituents at a shopping center when the gunman attacked, wounding several other people, including three of her staffers, several media reported.
"Ms. Giffords is alive. She is currently in surgery. There are nine other shooting victims at the hospital," University Medical Center spokeswoman Darci Slaten told AFP.
Witnesses said the lawmaker was shot at point-blank range.
National Public Radio said the suspect ran off and was tackled by a bystander before being taken into custody, and that witnesses described him as being in his late teens or early 20s.
Andrea Gooden, a witness who was in an office across the street, told Fox News she heard a burst of gunshots and "immediately after that there were people racing across the parking lot."
Another witness told CNN he heard 15-20 shots and saw people running from the scene and screaming before police and fire trucks arrived around two minutes later.
Footage from the scene showed paramedics rushing stretchers to helicopters.
The incident came after packages ignited in a post office in Washington, DC on Friday and two government buildings in neighboring Maryland on Thursday.
Giffords, 40, became the first Jewish woman to be elected to Congress from Arizona in 2006 and is married to Mark Kelly, a NASA astronaut.
She 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 favored a path to legalization that would require illegal immigrants to pass a criminal background check, pay back taxes and learn English.
Republican House Speaker John Boehner said he was "horrified" by the attack.
"Acts and threats of violence against public officials have no place in our society. Our prayers are with Congresswoman Giffords, her staff, all who were injured, and their families. This is a sad day for our country," he said in a statement.
Senior Democratic Representative Nancy Pelosi also condemned the attack.
"It is with the deepest sadness that we have received word of the attack on Congresswoman Gabrielle Giffords, members of her staff, and her constituents," she said in a statement.
"This terrible act of violence is a national tragedy, and today is a very sad day for our country."
The shooting came less than a week after Congress reconvened with Republicans in control of the House of Representatives and with an enhanced minority in the Senate following their route of President Barack Obama's Democrats in November elections.