Photo of the social media shows protesters near Tehran University on December 30.

:: Night protests have continued in the Iran’s capital Tehran and various other cities on Tuesday as clashes between protesters and police turned violent, especially in the northwest city of Mashhad and southern Shiraz.

Crowds began gathering in the early hours of Tuesday at the University of Tehran, where police attempted to block student protesters from convening near important squares on campus, many of whom chanted “Death to the dictator” as they gathered.

Protests began in Iran’s second largest city Mashhad and quickly spread to become the biggest challenge to the Islamic regime since mass demonstrations in 2009.

According to state television six people were killed in the central town of Qahderijan and one in Khomeini Shahr. In addition, a member of Basij militia and a police officer were killed in Najaf Abad on Monday.