Police believe the other robbers, who have bolted, may have sustained gun shot wounds.
Deputy Eastern regional Police commander ACP James Azumah Abass who confirmed the incident on Joy News said it happened Sunday 5pm between Jejeti and Nkawkaw.
The armed robbers fired shots into the commercial bus forcing it to ground to a halt and began the robbery spree. None of the passengers were hurt.
A security operative chanced on the scene and fired shots at the robbers.
Police patrol teams were deployed to the scene and after a sustained chase, managed to arrest three including one injured by the gun shots.
ACP James Azumah Abass wants anyone with information to contact the Eastern region police hotline on 0342022569 or the general hotline on 18555.
He wants doctors and nurses to be on the look out for anyone reporting to a health center for treatment of gun shot wounds.