Nearly 50 years after the 1979 Islamic Revolution overthrew his father, exiled Crown Prince Reza Pahlavi has spurred demonstrators onto the streets in a massive escalation of the protests sweeping Iran.

Iranian protests sparked by a currency collapse evolved into a broader uprising demanding regime overthrow, with demonstrators torching government buildings across provinces.

Iran was largely cut off from the outside world on Friday after authorities blacked out the internet to curb growing unrest, as video showed buildings ablaze in anti-government protests raging in several cities across the country.

New to these latest protests, however, is the chant: "Pahlavi will return," a reference to Reza Pahlavi, the son of the late Shah of Iran who was overthrown in 1979. It was he who called for people to turn out on the streets on Thursday night.

Iran has insisted for decades that its nuclear program is peaceful. However, its officials have increasingly threatened to pursue a nuclear weapon. Iran had been enriching uranium to near weapons-grade levels prior to the U.S. attack in June, making it the only country in the world without a nuclear weapons program to do so.

Iran's supreme leader Ayatollah Ali Khamenei on Friday insisted that the Islamic republic would "not back down" in the face of protests after the biggest rallies yet in an almost

BBC News Persian profiles the former crown prince who is once again seeking a role in shaping his country's future.

The demonstrations, now in their second week, have spread across the country as strikes hit Iran’s oil sector.