African Union and Somali troops launched a long-awaited assault Tuesday against the Al-Qaeda linked Shebab stronghold of Afgoye, the world\'s largest displaced people\'s camp, officials said. Residents reported intense clashes and heavy artillery fire on the outskirts of Mogadishu as tanks and troops pushed out in a pre-dawn attack from Deynile, a suburb of the capital. \"Early this morning, the African Union Mission in Somalia and the Somali National Army launched a carefully planned operation to bring security and stability to the people of the Afgoye corridor,\" an AU statement read. The troops are \"making good progress,\" the AU added, while the Somali army claimed that Shebab fighters were fleeing ahead of the advancing troops. \"The remnants of the Al-Qaeda militants have already suffered a major defeat and they have emptied their barracks in the area,\" said Mohamed Osmail, a Somali military official. \"The army cut off a key road on the outskirts of Deynile, which the enemy has been using when organising attacks and transporting fighters to undermine the security of the city, they are no longer there now,\" he added. Witnesses said civilians in the battle zone were fleeing the fighting. \"Several artillery rounds struck the KM13 area, and families who had remained in the area started fleeing this morning -- the fighting seems to be advancing on to Afgoye corridor,\" said Muhidiin Adan, a resident in Deynile. \"I saw two AU tanks crossing streets near Deynile airstrip... they want to cut off the supply routes of Al-Shebab,\" said Hassan Abdi, another resident. Deynile commands access to the Afgoye corridor, an area some 30 kilometres (20 miles) northwest of Mogadishu, which is controlled by the Shebab. Top Shebab official Sheikh Fuad Mohamed Shangole called on the people to rise up and attack the AU and government troops. \"The enemy wants to destroy the religion of Allah by attacking the mujahedeen fighters, be assured that the Army of Allah will win and the enemy will lose in the battle,\" Shangole told the group\'s radio Al-Andalus. \"I call on Muslims to unite to defend their religion and country from the enemy.\" Some 400,000 people, around one third of all the displaced people in Somalia, were still living in the Afgoye corridor at the start of the year, fleeing war or drought, according to figures from the UN refugee agency.