BBC Online :A senior Egyptian police officer has been killed by a bomb blast in the capital, Cairo, security officials say.Brig-Gen Ahmed Zaki died when an explosive device placed under his official vehicle was detonated in the western suburb of 6 October City.He was the fifth police general to be killed since the start of the year.Jihadist militants have stepped up attacks on security personnel and killed hundreds since the army ousted President Mohammed Morsi last July.A security source told BBC Arabic that an officer was also killed on Wednesday while chasing “terrorists” in the northern city of Alexandria.On Saturday, gunmen killed an intelligence officer and a policeman while patrolling a desert road linking Cairo to the canal city of Suez.The attack came a day after a policeman died in another bombing in the capital claimed by a group named Ajnad Misr (Egypt’s Soldiers).It says it is waging a campaign against police because of the state’s crackdown on Morsi’s Muslim Brotherhood, in which more than 1,300 people have been killed and 16,000 others detained.The insurgency threatens security ahead of May’s presidential election, which former military chief Abdul Fattah al-Sisi is expected to win.The retired field marshal has vowed to crush the militants.