[Updated at 5:55 a.m. ET] Six people have been arrested in connection with the shooting of Malala Yousufzai, the teenage activist who spoke out against the Taliban, though the main suspect still is on the loose, Pakistani police told CNN exclusively.

Police on Wednesday identified Atta Ullah Khan, a 23-year-old from the Swat district where Malala was attacked, as the main suspect. Authorities are searching for Khan, who was studying for a master's degree in chemistry, police say. The Taliban-heavy Swat Valley is in the northwestern part of Pakistan.

Six men accused of facilitating the attack were arrested, police said Wednesday. Also detained were Khan's fiancée, mother and brother, though they aren't accused of involvement in the attack, police said.

It's unclear whether Khan was at the scene and tried to shoot Malala or if he was considered the leader behind the plan to kill her.

Malala, who has become a global symbol of courage after being shot in the head by the Taliban for demanding education for girls, is currently receiving treatment at a hospital in Birmingham, England.

She stood with the aid of nurses Friday for the first time since the October 9 shooting and was "communicating very freely," according to the director of the hospital. Malala can't speak because she has a tracheotomy tube inserted to protect her airway, which was swollen after her gunshot injury, but she is writing coherent sentences, said Dave Rosser, director of University Hospitals Birmingham.

Friday's progress report - more detailed than previous updates - suggests that the 15-year-old could make a good recovery.

The Pakistani Taliban has claimed responsibility for the shooting and vowed to kill Malala if she recovers from her injuries.

Read more on Malala's story:

Attack on Pakistani schoolgirl galvanizes anti-Taliban feeling

Standing with Malala: Teen inspires others to fight for education

Malala: Global symbol, but still just a kid

$1 million bounty in Malala’s attack

The Malalas you'll never meet