Protesters also blocked the road near Rohini East Metro Station and raised anti-police slogans during their protest this morning.
In the demonstration, three people and a woman police official were injured after several protesters clashed with the police.
The incident had come to light last afternoon when the victim's mother went to the play school to pick her up. The girl pointed toward one Amit Tiwari (35) and alleged that he assaulted her regularly, a police official said.
"We are now scared that Tiwari might have done such crime with other students too," a protester said.
Meanwhile, police said that they are scanning the footages of CCTV installed in the premises of play-school to track Tiwari's movement inside the school.