Nigerian President Muhammadu Buhari has addressed the nation following three months of medical leave in the UK. In a televised speech, Mr Buhari, 74, said he was "distressed" by calls for the dissolution of Nigeria, urging Nigerians to come together. But the president failed to disclose his illness. It was his second spell of medical leave this year. Many Nigerians had called for him to resign during his absence, saying he was unfit to run the country. Others have called for more transparency over his condition, as speculation grew over whether he will...