Islamic State raises stakes with Egypt mosque attack

By Yusri Mohamed and Mahmoud MouradISMAILIA, Egypt (Reuters) - The mosque was packed with hundreds of worshippers for Friday prayers in Egypt's North Sinai when gunmen in military-style uniforms and masks appeared in a doorway and at windows.The ease with which they mounted an attack - killing more than 300 people in the worst bloodshed of its kind in Egypt's modern history - highlighted the threat militant groups pose in the most populous Arab country.After four years of battling Islamic State