Clashes between rival Islamist groups in Somalia’s capital Mogadishu have left dozens of people dead.The street battles in one of the world’s most violent cities pit pro-government fighters against more hardline Islamist opposition militiamen. Reports say at least 65 people have been killed and nearly 200 others injured in recent days. More than a dozen died on Sunday in a mortar attack on a mosque. In a country without effective central rule, Somalia’s interim administration is struggling with a powerful insurgency. In the latest fighting, rebels claim to have won control of contested areas, something denied by the government. Money from an international donors’ conference in Brussels last month aims to bolster security and fight piracy off Somalia’s shores. Himself a former Islamist rebel, President Sheikh Sharif Ahmed is widely seen as offering the best hope in years of restoring stability.