Washington, Jan 9 (DPA) A shooting at a grocery store in Tucson, in the US state of Arizona, left a US congresswoman and six others dead Saturday, reported broadcaster NPR Saturday.

The attack, for which the motive remains unknown, left at least five others wounded. Several of the wounded or dead include staff members travelling with the congresswoman, Democrat Gabrielle Giffords.

Giffords was at a previously scheduled citizen's outreach event at a grocery store when the shooting occurred. According to reports, she had been shot in the head and was initially responsive after the shooting.

A witness told CNN of a violent attack, with between 15 and 20 shots fired.

"It was like pots and pans falling around my ears. It was so loud," the man, who was at the event, told CNN.

Peter Michaels, news director with Arizona Public Media, told NPR that the gunman approached as Giffords was speaking to a couple and began firing from a little more than one metre's distance.

Initial reports also said the shooter had been taken into custody. He was described as being in his late teens or early 20s.

Giffords, 40, was a native of Tucson and had been in office since 2007. It is not unusual for members of the US legislature to attend citizen's events in their home districts during weekend breaks from Congress with little or no special security.

Giffords was married to Mark Kelly, an astronaut with the US space programme NASA, who is scheduled to captain the last flight of a space shuttle mission, scheduled for April.