CAIRO - Egypt's Prosecutor General Abdel Meguid Mahmoud ordered a media blackout on a probe over a New Year Eve bombing outside a church in the coastal city of Alexandria, which was blamed on a Palestinian group with links to al-Qaeda. Interior Minister Habib el-Adly blamed the attack on the Palestinian Islam Army, an extremist organisation based in the Gaza Strip in a bid to help Egyptian authorities ease escalating tensions between Muslims and Copts. "investigations into the Al-Qiddissein (Two Saints) Church bombing is necessary to be secret. Therefore, media outlets are urged not to air or publish anything related to it," read a statement from the Chief Prosecutor's office. It added that the probe, in which investigators and prosecutors are questioning more than 20 suspects, would stay 'top secret to keep evidence'. The Interior Ministry identified one of the suspects arrested as a 26-year-old Egyptian university student, who had travelled to Gaza and was enlisted by the militants to strike at Coptic churches. The Palestinian group has denied involvement. "Despite our praise to those who executed the attack, the Army of Islam has no connection to the Alexandria church bombing," the group said. The bomber in Alexandria died in the blast, which killed 24 Copts wounded dozens. Egyptians state security had pointed to possible foreign involvement, and officials said they were investigating several Palestinians who were perceived as possible threats.