Zimbabwe's President Robert Mugabe has made his first public appearance since the army took over on Wednesday, BBC report.He attended a graduation ceremony in the capital, Harare, handing out degrees. Mr Mugabe had been under house arrest for days. The army made its move after a power struggle over his successor. The military said on Friday it was "engaging" with Mr Mugabe and would advise the public on the outcome of talks "as soon as possible". Meanwhile Christopher Mutsvangwa - the leader of the influential war veterans' association, once loyal to Mr Mugabe - said he should step down at once. He called for a huge turnout in street protests on Saturday. "We want to restore our pride and tomorrow is the day... we can finish the job which the army started," Mr Mutsvangwa said. "There's no going back about Mugabe. He must leave." Liberal groups opposed to the president have also backed the rally.Image caption Mr Mugabe's attendance at the graduation is an annual tradition but he was not expected this year. BBC Online Africa editor Joseph Winter says he was allowed to be there partly to keep up the pretence that the military have not staged a coup and partly because of a genuine, deeply felt respect for him going back more than 40 years. Mr Mugabe walked slowly up a red carpet and joined the crowd in singing the national anthem, then opened the graduation ceremony at Zimbabwe's Open University, where he is chancellor. One of the people he conferred a degree upon was Marry Chiwenga, the wife of the general who detained him on Wednesday, the state broadcaster reports. Neither the 93-year-old president's wife, Grace Mugabe, nor Education Minister Jonathan Moyo - an ally of hers whose house was reportedly raided by the military - were present. The army acted after Mr Mugabe sacked Vice-President Emmerson Mnangagwa last week. Mr Mnangagwa was seen as a potential successor and his sacking was supposed to have paved the way for Grace Mugabe - who is four decades younger than him - to take over the presidency instead.