Iran: Three police officers die in clashes with dervishes

Three Iranian police officers have been killed in clashes with members of a Sufi Muslim religious community, police say.
A protest by dervishes at a police station in northern Tehran turned violent when the policemen were hit and killed by a bus.
Rights groups say Sufi dervishes have faced persecution in Iran.
One Iranian news agency described the incident as "deadly and bloody" and the dervishes as a "cult".
Nine protesters including the bus driver have been arrested, an Iranian police spokesman said.
BBC Persian posted a video of the incident on their Twitter account.
Videos published on social media before the incident showed dervishes holding a sit-in protest in front of a police station against the detention of one of their members.
A video posted on Twitter shows some protesters marching in the middle of the road and some others sitting on the road, holding banners with the photo of the arrested dervish, chanting "God is great."
Dervishes reported that the police used tear gas to disperse their gathering and videos on social media showed riot police chasing the protesters.