Egyptian authorities have arrested three more men for their suspected involvement with the bombing in Cairo on April 7, bringing to nine the number of detained suspects.
The bomb exploded in a bazaar in central Cairo killing four people, including an American, two French citizens and the bomber himself.
The perpetrator of the blast was identified through DNA tests last week as 18-year-old engineering student Hasan Rafat Bashandi. When police searched his house they found CDs with material downloaded from the Internet on how to build bombs. The security services believe the people now arrested recruited and trained Bashandi and helped in manufacturing the explosive device.
A fourth suspect, thought to be the mastermind of the attack, managed to flee, the Egyptian Interior Ministry said in a statement. It is believed he conned the bomber into thinking the bombing device had a delay mechanism which would give him sufficient time to flee the scene.
The attack was the first to target foreign tourists in seven years.