Mogadishu - Ethiopian troops in armoured vehicles crossed into two border towns in south central Somalia and seized the family of a man with links to al Shabaab insurgents, residents said on Sunday.

They said troops went to El Barde and Yeed on Saturday seeking the man. Washington says al Shabaab is al Qaeda's proxy in the region and which has declared loyalty to al Qaeda.

Ethiopia invaded its Horn of Africa neighbour with tacit U.S. support at the end of 2006 to oust an Islamist movement that was running the capital Mogadishu and much of the south.

The Ethiopian military officially withdrew in January last year.

Officials in Addis Ababa routinely deny that Ethiopian soldiers are on Somali soil, although they say they are providing security advice and training for Somalia's forces.