ROUGH CUT (NO REPORTER NARRATION)<br/> <br />Islamist militants were reported to have attacked a cordon of security forces surrounding an area where supporters of army chief General Abdel Fatah al-Sisi celebrated the anniversary of Egypt's 2011 uprising on Saturday.<br/> <br />The militants were said to have fired a rocket propelled grenade towards a police vehicle. One police officer was injured, according to a Reuters witness.<br/> <br />Security forces and militants exchanged gunfire and dozens of people were seen fleeing the site of the celebrations.<br/> <br />Nine people were taken to hospital with minor injuries, mostly from shock.<br/> <br />Twenty-nine people were killed during anti-government marches in Cairo and elsewhere while thousands more rallied in support of Sisi.<br/> <br />Sinai-based Islamist militants have stepped up attacks against security forces since Sisi toppled Mohamed Mursi of the Muslim Brotherhood in July after mass protests against his rule.<br/> <br />Tensions have been smouldering anew s
