More than 20 people killed and scores others injured when militia loyal to Islamic movement engaged government and Ethiopian troops in Somalia's capital Mogadishu. Fighting between Ethiopian troops and Somali insurgents flared again in Mogadishu on Thursday (April 19), killing at least 12 people and injuring scores others as residents flee the areas held by the Islamic and clan militia. Heavy shelling was heard around the coastal capital as scores of wounded were rushed to hospitals. It was not clear what triggered the latest battle. Ethiopian and Somali troops are dug in close to insurgent positions at various flashpoints across Mogadishu. Several missiles slammed into the Al Barakah market when it was crowded with shoppers. It was unclear how many people were injured or killed at the market. Vehicles mounted with machine guns by Islamic and clan militia could be seen moving the fighters to the fighting areas while bringing back the injured. The insurgents, drawn from the local Hawiye clan and a militant Islamist movement, are fighting the interim government, its Ethiopian military backers and African Union peacekeepers for control of a city in chaos for the last 16 years. Four days of ferocious fighting killed 1,000 people at the end of March and a truce since then has failed to prevent sporadic clashes. Ethiopian and Somali government troops ousted the Islamist movement -- which had Hawiye backing and ruled much of southern Somalia for the second half of 2006 -- from Mogadishu in a brief war over the New Year. The interim government, established in Kenya in 2004, is the 14th attempt to set up central rule in Somalia since the Horn of Africa nation slid into warlord-fuelled anarchy with the toppling of dictator Mohamed Siad Barre in 1991.