By Sahal Abdulle MOGADISHU, March 10 (Reuters) - Newly-trained security forces clashed with police at a Mogadishu police station on Saturday in a gunbattle that killed one person and wounded two, witnesses said. The incident was a reminder of the size of the task faced by Ugandan soldiers, the vanguard of an African Union (AU) force that started arriving this week to tame the anarchy that has usually reigned in the Somali capital since 1991. "A stray bullet came from nowhere. Tensions were high and there was firing from both sides," said local reporter Abdullahi Addow, who was inside the police station at the time. A security source said one policeman was killed and two security troops were wounded in the brief clash that took place when about 1,500 new forces turned up for duty at the police station in an eastern suburb of the coastal city. Many residents say insecurity is worsening in Mogadishu, with shootings and almost daily assaults on government forces and their Ethiopian allies, who defeated militant Islamists in a swift December offensive. The Ugandan soldiers were attacked almost as soon as they started landing on Tuesday, and two were wounded in an ambush the following day -- raising the spectre of the last peacekeeping mission to Somalia, which ended in failure in 1995. More than a decade ago, well-armed and well-funded U.S. and U.N. troops were forced to withdraw from Somalia after relentless street battles with militiamen. CLAIM The self-styled Popular Resistance Movement has claimed responsibility for the assaults against the Ugandans. The authenticity of the claim could not be independently verified. "These groups and their threats have always been there. It's nothing new," Ugandan Minister of State for Defence Ruth Nankabirwa told Reuters in Kampala. The AU has started investigating the cause of a small fire on one of its planes on Friday and could not rule out whether "negative elements" were behind it, an AU spokesman said. The proposed 8,000-strong AU mission, facing a shortage of money and equipment, is meant to replace Ethiopian forces who have started pulling out of a country where they are viewed by many Somalis as invaders. "Our withdrawal is not contingent to the deployment of the African mission," said Ethiopian Foreign Minister Seyoum Mesfin. "But of course we have to withdraw leaving a situation that would not lead us again into sliding back," he told reporters. Diplomats say the Somali interim government's credibility hinges on pacifying Mogadishu -- one of the world's most gun-infested cities -- and extending its shaky authority over a country deprived of central rule since warlords toppled dictator Mohamed Siad Barre in 1991. There have been 13 unsuccessful attempts to establish a central government since then. (Additional reporting by Tim Cocks in Kampala and Andrew Cawthorne in Mekele, Ethiopia)
