EGYPT'S State Security prosecutors started yesterday questioning 15 Islamists, including the Deputy Supreme Guide of the Muslim Brotherhood, who were detained on Monday for belonging to a banned group and holding secret meetings. "The suspects arrived at the State Security prosecutors in New Cairo court compound from different governorates. They are questioned over affiliating to a banned organisation," a legal source said. He added that the suspects were accused of holding secret meetings to discuss spreading ideas of their banned group and were preparing documents to circulate. State Security Police had arrested Mahmoud Ezzat, the Deputy Supreme Guide of the Brotherhood; and Essam el-Erian and Abdel Rahman el-Barr, a leading member of the 16-strong Guidance Bureau. A spokesman for the Muslim Brotherhood said the arrests were an attempt by the authorities to thwart its preparations for elections later in the year. The group holds 20 per cent of seats in Parliament, making it the country's largest opposition bloc. However, its members pose an independent as the group is outlawed under the Egyptian constitution. A new round of parliamentary elections will hold next October.