Somalia's parliament is due to start choosing a new president, in the latest step to end decades of war. The newly-elected MPs will convene at a police academy in Mogadishu for the secret ballot, according to the (BCC). Among the 25 contenders are incumbent President Sharif Sheikh Ahmed and Prime Minister Abdiweli Mohamed Ali. It is the first time in many years that the vote has taken place on Somali soil, a sign that security is improving, correspondents say. To win in the first round of voting, a candidate needs to secure a two-thirds majority. A simple majority is required in the second round. Current Islamist President Sheikh Sharif Sheikh Ahmed, in power since 2009, is regarded as a favourite. The president's opponents have accused him of corruption - a charge he has repeatedly denied. Despite fears that the poll may be flawed, many Somalis welcomed the move. Since the overthrow of President Siad Barre in 1991, Somalia has seen warlords, Islamist militants and its neighbours all taking a hand in its affairs. With the help of African Union troops, the interim government has been able to gain control of the capital. However, al-Shabab - an armed group that has joined al-Qaeda - still runs many central and southern areas of the country.