A third explosion has been reported outside a police station in Cairo, hours after a car bomb killed at least four people and a second explosion in the Egyptian capital killed a police officer.
There were no immediate reports of casualties from the third blast, which was heard in the Talbeya neighbourhood in the suburb of Giza.
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The annual event has earned a place in the record books ahead of the grand final of the 60th anniversary show in Austria this evening.
Local authorities said the move is necessary to "avert the growing number of deaths and increasing harm linked to psychoactive substances".
Some students argued that the centuries-old tradition of wearing gowns, suits and mortarboards to exams was 'archaic' and looked elitist.