Thousands of residents fled the Somali capital on Saturday, many on foot and carrying children on their backs, after days of fierce fighting between government troops and Islamist rebels. The exodus was the heaviest since the UN-backed shaky government of President Sharif Sheikh Ahmed took office five months ago, an selfnews correspondent said. Fighting broke out Friday afternoon in hitherto unaffected northern district of Karan in which a lawmaker, Mohamed Husein Addow, was killed: the third senior official to be killed in as many days. Addow was reportedly captured and executed by gunmen. The previous day, Mogadishu's top police commander -- described as a faithful ally to Sharif -- was also killed in a fierce battle in the capital. Omar Hashi Aden, a key member of Ahmed's embattled transitional administration, was among 20 people killed when a suicide bomber rammed his vehicle into a hotel in Beledweyne, north of Mogadishu, on Thursday. Residents reported sporadic gunfire on Saturday morning in Karan, prompting a mass exodus. 'This is the worst moment of our lives. I don't need to describe the conditions in Karan, just look at me,' said Mohamed Ali Osman, 23, who had his 18-month daughter strapped on his back and was carrying a heavy sack of corn flour on his head as he walked out of the city. 'My wife and three other children fled yesterday, but I was trapped indoors with my daughter here,' he added. Others took any means of transport available, including donkey carts and open trucks, to escape the fighting. Many of the displaced are fleeing to Afgooye corridor, about 20 kilometres (12 miles) south of the capital and where many sleep in the open by the roadside. Aid agencies say at least 400,000 displaced are living rough there. Around 300 people, many of them civilians, have been killed in the six-week-old battle and more than 125,000 displaced, according to UN figures and casualty tolls compiled by selfnews. The drive against Sharif's administration has been spearheaded by the hardline Shebab armed group and the more political Hezb al-Islam (Party of Islam) of Sheikh Hassan Dahir Aweys, a former Sharif ally. Aweys and the Shebab, who were among the main targets of Ethiopia's 2006 military invasion, have refused to join peace efforts despite Ethiopia's January pullout. They argue that the African Union's 4,300 Ugandan and Burundian peacekepeers are an occupation force bent on imposing Christianity in Somalia. 