Somalia's special forces have killed all three gunmen who had taken over a building in central Mogadishu, using civilians as human shields, officials say. The attack, which killed 20 people, began late on Thursday when al-Shabab militants stormed an area lined with hotels, shops and restaurants. They then seized a nearby building. This was the longest siege by the militant group since it was forced out of the Somali capital in 2011. The final gunman was killed on Friday evening, about 22 hours after the initial attack. Ismail Muktar, the commissioner for Hamar Jajab district, told reporters about the final moments of the siege. "The last terrorist gunman was killed after the security forces destroyed a room in which he was taking cover and the siege is over now," he said. Al-Shabab has said it was behind the attack in the busy Maka al-Mukarama road, which has also injured more than 60. A number of civilians were rescued from the building. There are fears that the death toll could rise further. AFP.