At least 21 Somali civilians were killed Thursday and 59 wounded in fierce Mogadishu clashes pitting government forces backed by African Union troops against Islamist insurgents, medics said. The fighting broke out when newly-trained government forces backed by the soldiers of the African Union mission in Somalia (AMISOM) apparently launched a major offensive to recapture key Mogadishu neighbourhoods. The internationally-backed government had lost ground last month when insurgents, mainly from the Al Qaeda-inspired Shebab movement, punched through a strategic frontline and closed in on the presidential compound. "The Somali government forces advanced on the terrorists' strongholds this morning," Colonel Ahmed Ibrahim, a government security official, told a foreign news agency.