Witnesses say an armed mob has attacked the US consulate in the Libyan city of Benghazi and set fire to the building in what they say was a protest at a film deemed offensive to Islam's Prophet Muhammad. Just hours earlier on Tuesday, thousands of Egyptian demonstrators apparently angry over the same film - an amateur film produced by expatriate members of Egypt's Christian minority resident in the US - tore down the Stars and Stripes at the US embassy in Cairo and replaced it with an Islamic flag. Al Jazeera's Sherine Tadros reports from Cairo.