(Adds details) MOGADISHU, Jan 2 (Reuters) - Somali Prime Minister Ali Mohamed Gedi said on Tuesday Eritrean, Ethiopian rebel and Arab fighters were taken prisoner during the ousting of Islamists who held southern Somalia for six months. "Yesterday, we have captured Eritreans, Oromo and Arab fighters," he said, referring to rebels from Ethiopia's Oromia region. "This is a clear sign foreign fighters are involved." The Somali government, and its Ethiopian backers, have long said several thousand foreign fighters were aiding the Islamist movement which took Mogadishu and most of south Somalia in June but was defeated at its last bastion on Monday. Addis Ababa has particularly pointed the finger at its arch-enemy Eritrea, saying it sent hundreds of soldiers to fight alongside the Somalia Islamic Courts Council (SICC). Asmara denies that, saying Ethiopia has planted fake Eritrean identity cards in Somalia to try and smear it. Gedi said there would be no mercy for foreign radicals caught in Somalia, although locals who fought with the Islamists would be pardoned if they put down their weapons. "All foreign fighters will face a court and Somalis will be given an amnesty," he told a news conference. He did not say how many foreign prisoners his government had captured. The prime minister added that Ethiopian troops would leave once the country was stabilised. "The Ethiopians will leave when they clear terrorists and pacify Somalia," he said. "It will be a week, or weeks and months, not more." Gedi added that Somalia had re-opened its airspace. "If an airline wants to come they need clearance from the proper institutions. Somali airspace is open for humanitarian flights, but they must also give us their information ahead of time," he said.
