Image caption Mrs Giffords, aged 40, remains in critical condition

US Congresswoman Gabrielle Giffords - who was shot in the head by a gunman last week - has been taken off a ventilator, hospital officials say.

They say they now inserted a tracheotomy tube in her windpipe to protect her airways, freeing her from the breathing tube.

Mrs Giffords had been breathing on her own since the shooting in Tucson, Arizona, but the breathing tube had been left until now as a precaution.

Six people died in the shooting.

The gunman, 22-year-old Jared Loughner, opened fire as Mrs Giffords was holding a constituency meeting on 8 January. More than a dozen people were also injured before the gunman was overpowered.

Mrs Giffords - who has since had brain surgery - remains in critical condition but appears to be recovering, the doctors say.

On Saturday, the doctors also inserted a feeding tube to provide nutrition.

Mr Loughner has been charged with several offences and could face the death penalty if found guilty.

The shooting sent shockwaves across the United States.