(Adds Baidoa attack, speaker visit) By Andrew Cawthorne NAIROBI, Dec 6 (Reuters) - Somali President Abdullahi Yusuf is recovering well from bronchitis in a Nairobi hospital and will fly to Britain soon for a check-up on his liver transplant, the Somali ambassador to Kenya said on Thursday. Suggestions by some security and diplomatic sources that Yusuf was in very serious condition were "lies", the envoy, Mohamed Ali Nur, told Reuters after a morning visit to the hospital where the president has been since Tuesday. "He is doing well and is very upbeat. He was walking and exercising in his room," Nur said, noting that the stress of Somalia's political turmoil had contributed to the infection. "In the last four weeks, he has had a lot of stress. He was busy with the appointment of the new prime minister and cabinet. He had slept very little. All this made him very tired." Yusuf also met with Somalia's parliament speaker, Sheikh Adan Madobe, on Thursday, presidential aides said. A government source who visited Yusuf late on Wednesday said the former warlord was well enough to make jokes. "I don't think someone who is cracking jokes is in a serious condition. He is just resting before he goes to Europe," he said. Yusuf, who gives his age as 72 but is said by some to be nearer 80, would take the next available flight to the United Kingdom, on Thursday or Friday, for his annual check-up related to a liver transplant he had 13 years ago, Nur said. MEDIA RESTRICTIONS EASE Yusuf leads a government that is the 14th attempt to restore central rule in Somalia since the 1991 toppling of dictator Mohamed Siad Barre. This year, his administration has faced an Islamist-led insurgency, political infighting and a humanitarian crisis a U.N. envoy called the worst in Africa. Hundreds of thousands of people have fled their homes in the conflict that a Somali rights group says has killed 6,000 civilians this year. One person was killed on Thursday in an attack on Ethiopian-backed government troops in Baidoa, the southern trading town where parliament is based, a witness said. "I saw one civilian killed after a grenade was hurled at an Ethiopian military vehicle. The incident took place in the centre of Baidoa town," he told Reuters. Later, another five people were wounded in a grenade attack in Baidoa's city council centre, officials said. "Four city council employees and one civilian have been wounded in the grenade explosion. It happened in the afternoon," Baidoa Governor Bashir Hashi Gabow said. In another development, three private radio stations in Mogadishu were back on the air on Thursday after a deal was struck with the capital's authorities, who have in the past accused local broadcasters of backing the insurgents. Shabelle, Simba and Banadir radio stations were ordered off the air some three weeks ago, in a move condemned by media watchdogs. But the ban was lifted after they, along with at least five others, signed an 18-point agreement with the mayor. The deal appeared to give the press some concessions. For example, the media are now allowed to report on military operations in the country if they contact government officials about them. Journalists are also now able to cover rallies and demonstrations if they secure permission from the organisers. (Additional reporting by Aweys Yusuf in Mogadishu and Ahmed Mohamed in Baidoa; Editing by Bryson Hull and Sami Aboudi)