The April 2005 attacks in Cairo were three related incidents that took place in Cairo on 7 April and 30 April 2005 . Two incidents caused no loss of life other than those of the perpetrators and appear not to have been planned in advance ; in the first attack , however , three bystanders were killed . Two groups claimed responsibility - the Mujahedeen of Egypt and the Abdullah Azzam Brigades . In its statement , the latter group said the attacks were in retaliation for the government 's clampdown on dissidents in the wake of the Sinai Peninsula bombings . In the early hours of 1 May , security forces arrested some 225 individuals for questioning , mostly from the dead three 's home villages and from the area where they lived in Shubra . Particularly keenly sought was Muhammad Yassin , the teenage brother of Ehab Yousri Yassin , whom the police described as the only remaining suspect in the bazaar bomb attack and a material witness to the shooting . Over the course of the weekend , it also emerged that all the attackers were relatives of Ashraf Said , a suspect in the 7 April bombing who was taken in for questioning and died in police custody on 29 April
Sinai Peninsula bombings
2004 Sinai bombings
Terrorism in Egypt