Image caption Ms Giffords will continue daily rehab sessions at the hospital, her husband said in a statement

The US congresswoman shot in the head in January has been released from hospital to begin outpatient treatment after improvements in her condition.

Gabrielle Giffords of Arizona is to move to the Texas home of her husband, astronaut Mark Kelly.

Six died and 13 were injured in the shooting at Ms Giffords' constituent event in Tucson, Arizona.

The man accused of shooting Ms Giffords and killing six others has been found mentally unfit to stand trial.

"Congresswoman Giffords has shown clear, continuous improvement from the moment she arrived at TIRR five months ago," Dr Gerard Francisco, the hospital's chief medical officer, said in a statement.

"We are very excited that she has reached the next phase of her rehabilitation and can begin outpatient treatment. We have no doubt that she will continue to make significant strides in her recovery."

Speaking impaired

Last month, Ms Giffords, 41, underwent surgery to replace a portion of her skull with a ceramic implant, with a device permanently implanted in her skull to drain fluids.

On Sunday, Ms Giffords' aides released the first photographs of her since the shooting. In the images, she was smiling and appeared clear-eyed.

But in an interview with The Arizona Republic published last week, Ms Giffords' chief of staff Pia Carusone said she still had only limited speaking ability.

Jared Loughner, the man accused of shooting Ms Giffords, is being held in a mental health facility while doctors attempt to treat him so he can be tried for the attack.

He has pleaded not guilty.