Cairo. Supporters of the Muslim Brotherhood yesterday protested across Egypt against the country’s military-backed interim government, amid a heavy security deployment.Protests were reported in Nasr City and Mohandiseen in the capital, Cairo, as well as in Giza and several governorates in the Nile Delta. Protesters also rallied in Shoubra al-Kheima in Qalyoubia, just outside of the capital.Security forces have shut all roads leading to Rabaa al-Adawiya mosque, where protesters supporting deposed President Mohamed Morsi were forcibly dispersed on August 14, the state-run MENA news agency reported.Roads leading to central Cairo’s Tahrir Square, Ramses Square and the defence ministry were also closed.Riot police blocked off Qaid Ibrahim mosque in the coastal city of Alexandria, as well as al-Iman mosque in eastern Cairo, ahead of the demonstrations.The Brotherhood’s call for mass protests and sit-ins on Friday was a measure of how much an ongoing security crackdown has crippled the group. Security forces have accused the Islamist group of using rallies to create chaos.The interior ministry said in a nationally televised statement on Thursday that its forces would respond with "firmness” against acts that threaten national security, and that police had orders to use deadly force in defence of public and private property.The Brotherhood released a four-page statement in Arabic on Thursday, part of which called on security forces to disobey orders "to kill”.Meanwhile, Egypt’s state news agency says unidentified gunmen in two cars opened fire on a police station in the upscale Cairo neighbourhood of Heliopolis, killing an officer.Authorities continued to hunt down senior Islamist leaders, arresting two top Brotherhood figures, including Mohamed el-Beltagy on Thursday.Beltagy, a former member of parliament and head of the Brotherhood’s Freedom and Justice Party, was wanted on accusations that he incited violence and had been on the run for nearly three weeks.Violence in Egypt peaked on August 14 when police, backed by snipers and bulldozers, attacked two Brotherhood-led sit-ins in the capital. The move caused days of nationwide violence that has killed more than 1,000 people, most of them Morsi’s supporters.