(Adds details) NAIROBI, Dec 4 (Reuters) - Somali President Abdullahi Yusuf is in "serious" condition at a hospital in the Kenyan capital, a security official said on Tuesday. "He is in what you would classify as a serious condition. He flew into Nairobi this morning and went straight to Nairobi Hospital," the security official said, on condition of anonymity. An aide close to the president, who declined to be named, confirmed Yusuf was in the hospital, but said he was in "fine condition, thanks be to God". Yusuf is a long-surviving liver transplant patient who has had to go abroad for specialised medical treatment. He was due to go to London this week for a checkup. (Editing by Michael Winfrey)
