Egyptian authorities at Cairo airport banned on Sunday Sudans leading opposition leader Sadiq al-Mahdi from entering the country after he returned from a trip to Germany. Egyptian authorities and the Sudanese ambassador to Cairo refused to comment. Al-Mahdi has been residing in Cairo since March and Egyptian authorities have allowed him to travel during this period. The Ummah Party, which Mahdi heads, said security stopped him from entering the country as he returned to Cairo after participating at an opposition conference of the Sudan Appeal Forces in Berlin with German authorities to discuss political crisis in the country. The statement explained that Mahdi was held at the airport for more than 10 hours waiting to organize his departure to another country. It added that he was denied entry over Egyptian requests for him not to participate in the Sudanese opposition conference. Mahdi saw the move as “external dictations in Sudanese internal matters,” according to the statement of the Ummah Party. Mahdi also heads the Sudan Appeal, an opposition coalition that includes civil parties, armed movements and civil society organizations. The party "regretted the Egyptian action" and said it may damage the future of relations between the peoples of both countries. Egyptian and Sudanese sources said Mahdi went to London after he was denied entry to Egypt. Sudanese and Egyptian authorities have accused each other of harboring dissidents, but this is the first time that Cairo has banned a prominent Sudanese opposition figure.