cairo egypt hang 15 men convict attack kill security force sinai peninsula security source say tuesday appear large number executions single day since president abdel fattah al-sisi take office 2014. hang take place two prisons north country early tuesday source say military court issue sentence interior ministry officials carry executions simultaneously borj al-arab wadi al-natroun prisons source say militants sinai region accuse join militant group take part carry plan assist kill number army police personnel sinai source say islamic state sinai branch wag attack security force years-long insurgency north sinai past year expand target include christians civilians attack mosque last month kill 300 people deadly egypt modern history widely attribute islamic state group claim responsibility 2015 six people execute kill two soldier raid qalyubiah province north cairo egypt hang 15 militants kill security force sinai security source