MOGADISHU, Jan 18 (Reuters) - At least four people were killed and 10 others injured on Tuesday in Somalia"s capital Mogadishu in a suicide bombing at a tea-shop near a military base, state-run SONNA news agency said, and Islamist group al Shabaab claimed responsibility. Patrons, who included both soldiers and civilians, were sipping tea when the bomber blew himself up, local residents told Reuters. One resident, Ahmed Ismail, said he heard the blast but that when he ran towards the scene to find out what had happened he was blocked by soldiers. The Nacnac base outside which the blast occurred is located near a Turkish military garrison which helps to train Somali troops. "A mujahid bomber targeted the tea shop in which there were Somali soldiers trained by Turkey," al Shabaab"s military operations spokesman Abdiasis Abu Musab told Reuters, adding that the number of victims both dead and injured were 20. Al Shabaab frequently carries out bombings and gun assaults in Mogadishu and elsewhere in Somalia. The group wants to topple Somalia"s central government and establish its own rule based on its own strict interpretation of Islamic Sharia law.