At least five people were killed and eight more were wounded in a suicide bombing in Mogadishu on Tuesday, Somali police said. The incident occurred after a suicide bomber detonated an explosive belt near a police academy, police spokesman Sadiq Adan Ali said. Mr Ali said the bomber targeted a restaurant frequented by police. The Somalia-based Al Shabab terrorist group often targets the capital city. The United Nations has warned that the Al Qaeda-affiliated group is improving its explosive-making skills. Last week, the UN voted to prevent the sale or shipment to Somalia of components of improvised explosive devices if there is “significant risk” they may be used in terrorist attacks. <br/> Al Shabab remains the most active and resilient extremist group in Africa, controlling swathes of southern and central Somalia.<br/> It has fired several mortars this year at the heavily defended international airport, where the US Embassy and other missions are located. Meanwhile, the Trump administration on Tuesday moved to slap new sanctions on the African extremist group. The State Department announced it had imposed sanctions on two senior leaders of the group, which was designated a “foreign terrorist organisation” in 2008. The State Department said it had identified Abdullahi Osman Mohamed and Maalim Ayman as “specially designated global terrorists”, a step that freezes any assets they may have in US jurisdictions and bans Americans from doing any business with them. It said Mohamed is the group’s senior explosives expert, special adviser to the so-called “emir” of Al Shabab and leader of its media wing, Al Kataib. Ayman is the leader of Jaysh Ayman, an Al Shabab unit conducting attacks and operations in Kenya and Somalia, including one in January on a military base in Kenya that killed one American soldier and two US contractors, the State Department said.