Demonstrators clashed with police in the Pakistani city of Peshawar on Friday as anger over insults to the Prophet Mohammad boiled over despite calls from political and religious leaders across the Muslim world for peaceful protest.Western diplomatic missions throughout the Muslim world tightened security, with some closing down on expectation of big protests after Friday prayers.An anti-Islam film made in America has enraged Muslims and led to days of protests across the Muslim world while cartoons mocking the Prophet Mohammad published in a French magazine on Wednesday were expected to compound the anger.Egypt’s highest Islamic legal official said on Thursday Muslims should follow his example of enduring insults without retaliating.But the call looked unlikely to calm the outrage."An attack upon the Holy Prophet is an attack on the whole 1.5 billion Muslims. Therefore, this is something unacceptable,” Pakistani Prime Minister Raja Pervez Ashraf said in a speech to politicians, religious leaders and others.Pakistan has declared Friday a "Day of Love for the Prophet Mohammad”. Critics of the unpopular government said it was pandering to Islamist parties.Protesters took to the streets of the Pakistani city of Peshawar, an old frontier town on the main road to Afghanistan, and torched two cinemas and clashed with riot police who tried to disperse them with teargas.