Egyptian Interim Prime Minister Hazem el-Beblawi Tuesday declared Muslim Brotherhood, the country's oldest and most influential Islamist movement, as a terrorist group, official news agency MENA reported. The announcement came after a powerful explosion ripped through a security headquarters in Egypt's Nile Delta city of Mansoura early Tuesday, killing at least 14 people and injuring 130 others. Most of the victims were police conscripts. "The Brotherhood has shown its ugly face as a terrorist group and its acts will not weaken the Egyptian people's determination to move forward," Beblawi was quoted by his media adviser Sherif Shawqi as saying. In October, the Egyptian authorities ordered to remove the Muslim Brotherhood from a government list of accredited non-governmental organizations. Earlier, a Cairo court also ordered to ban all activities of the Brotherhood group, seize its funds and form a panel to administer its assets.