A bomb blast hit a bus in Cairo's Nasr City district on Thursday (December 26), injuring four people, a spokesman for Egypt's interior ministry told Reuters, two days after a car bomb killed 16 in the Nile Delta.<br/> <br />The homemade device had been put on a traffic island and a second one, found nearby, was being dismantled, Hani Abdel Latif said. State television showed footage of a bus with its windows blown out.<br/> <br />Attacks across Egypt over the last few days have raised fears of intensifying violence in the run-up to a constitutional referendum in January as the interim government pushes ahead with an army-backed plan for political transition.<br/> <br />The government has vowed to fight "black terrorism" after Tuesday's deadly attack on a police compound in the city of Mansoura which also injured about 140 people.<br/> <br />Bomb attacks and shootings have become an almost daily occurrence in the Sinai peninsula since the army toppled Islamist President Mohamed Mursi in July following mass
