Somalia’s al shabaab Islamist group driven out of major strongholds

An African Union Mission in Somalia (AMISOM) tank drives to position during fighting against Islamist insurgents al Shabaab in Suqa Holaha village of Horiwaa district, northern Mogadishu March 3, 2012. [PHOTO/REUTERS]

A military offensive has driven Somalia's al Shabaab Islamist group out of major strongholds and deprived it of revenue sources, but its retreat to a southern valley and northern hills still poses a threat, the U.N. envoy to Somalia said.

The African Union's AMISOM peacekeeping force and Somali soldiers have pushed the group, which wants to topple the Western-backed government, into smaller pockets of territory since launching an offensive last year.