Coptic Christians in Egypt have clashed with riot police, a day after 21 Christians were killed in a bomb attack on their church in the city of Alexandria. Hundreds of Christian protesters in Alexandria and Cairo demanded that the Egyptian authorities do more to protect their community from militant attacks. Egyptian authorities are questioning seven people over the blasts which they have blamed on foreign elements. Meanwhile, the top Muslim cleric in Egypt, Sheikh Ahmed el Tayeb, has accused Pope Benedict of interfering in Egypt's internal affairs. The grand Imam of Al Azhar criticised Pope Benedict's New Year call for world leaders to protect Christians in the Middle East. The Vatican immediately rejected the accusation.