Iranian President Hassan Rouhani has given his first public reaction to four days of anti-government protests. He says Iranians have the right to protest but they must avoid violence as well.

HASSAN ROUHANI IRANIAN PRESIDENT "In recent days, we have witnessed some protests. Everyone must be aware of this point that we are a free nation and according to the constitution and human rights, the people are absolutely free to criticize the government and even to protest. But their protests should be done in such a way as to aim at the end to improve the situation in the country."

Anti-government protesters demonstrated on Sunday in defiance of a warning by the authorities of a tough crackdown. Iran is gripped in one of the most audacious challenges to the clerical leadership since pro-reform unrest in 2009. Tens of thousands of people have protested across the country since Thursday. Their anger is directed against the Islamic Republic's unelected clerical elite and Iranian foreign policy in the region.