WATCH: Iranian policewoman attacks student because of her hijab

A video circulating on social media has shown Iranian police chasing a number of women and girls because of their dress, trying to impose a certain way of wearing the hijab.

The video, which first surfaced on Tuesday, shows the female members of the religious police chasing a school girl until she hopped onto a bus, speaking violently with her because of the way she is wearing her hijab.

One of the religious policewomen was seen pushing the school girl inside the bus and forcing her to sign a document pledging that she will stick to the rules, which led to the girl breaking down in tears and begging the policewoman to leave her alone as she has exams, as shown in the video.

This scene led one of the schoolgirls to come forward to defend her colleague, sitting next to her and calming her down and pointing to the policewoman in a defying gesture.

These incidents happens very often in Iran, prompting activists to launch the "White Wednesday" initiative to express rejection of the obligatory headscarf imposed by the laws in force since the Islamic Revolution in 1979.

Since last December, more than 30 Iranian women have been arrested because of attempts to remove their hijab publicly in a move to defy the law. Iranian authorities has released most of them but they are still undergoing trial.