Egyptian security officials say a senior police officer has died after an explosive device placed under his car went off in a western Cairo suburb. The officials say Brig. Gen. Ahmed Zaki was heading to work from his home in 6th of October suburb when the bomb detonated on Wednesday morning. The officials say the explosion critically wounded Zaki and he later died in the hospital. The officials spoke on condition of anonymity because they were not authorized to speak to media. Attacks against Egyptian police and military have stepped up as militant groups wage an increasingly violent campaign following the ouster of Islamist President Mohammed Morsi. Since Morsi was removed by the military last July, more than 1,300 protesters, mostly pro-Morsi supporters, and over 450 troops have been killed.