CAIRO : A roadside bomb killed two Egyptian policemen and wounded nine in the town of El Arish in the restive north of the Sinai Peninsula late Thursday, security officials said. Sinai-based militants have killed scores of policemen and soldiers since the military overthrew Islamist president Mohamed Morsi in July last year. The attacks have spread to the capital and other parts of Egypt , despite a sweeping police crackdown on the militants. Twin bombs near a mosque in the Nile Delta on Thursday night wounded 11 people, including a policeman, the state MENA news agency reported. The bombs struck during a Sufi Muslim festival in the city of Tanta, two days after a bomb in central Cairo wounded 12 people.