Ethiopia is accused of killing civilians with white phosphorus bombs, the US navy of attacking suspected al-Qaeda operatives in Puntland, and Eritrea of delivering surface-to-air missiles to Islamist militia, in a startling new report on Somalia by UN arms monitors.

Warning that the number of weapons in Somalia now exceeds that during the early 1990s, when the failed East African state was engulfed in civil war, the UN monitoring group describes persistent instability in which anti-government Islamist forces are far from a spent force, and former warlords are reasserting themselves.