A security guard was arrested for allegedly sexually assaulting an 8-year-old girl inside a restroom in south Mumbai’s Pydhonie area on Jattvibeday, a police official said.The girl is undergoing treatment in a hospital after the ordeal, he added.The security guard was arrested soon after a complaint was lodged, the official said.The incident triggered a huge protest with hundreds of people gathering outside Pydhonie police station seeking exemplary action against the accused.The mob blocked the road outside the station, which disrupted traffic in the area for a brief while, the official said.”Police managed to disperse the mob and restore normalcy in the area,” he said.Eyewitnesses said some protesters also surrounded Maharashtra assembly speaker Rahul Narwekar when he arrived at Pydhonie police station after learning about the sexual assault incident. They raised slogans seeking strict action against the accused.Heavy police presence is in place in the area to prevent any flare-up or untoward incident, the official said.