Updated

Columns of African Union and Somali troops are moving deeper into land controlled by al-Qaida-linked militants, forcing fighters to flee from five towns in quick succession.

Al-Shabab has put up little resistance as the AU and Somali troops surged toward their strongholds over the last several days. Though al-Shabab's reclusive leader, Ahmed Abdi Godane, spoke on the militants' radio station and urged Somalis to join their ranks and fight against the offensive.

Somali President Hassan Sheikh Mohamud said in a statement Monday that the offensive will help foster an environment conducive to good governance. The U.S. State Department applauded the military push.

After controlling most of the capital for years, al-Shabab was pushed out in August 2011, allowing an era of relative peace. Insurgent attacks have recently increased.