MOGADISHU (Reuters) - African Union and Somali government troops stepped up their assault on al Shabaab militants in the capital's northern outskirts on Wednesday, forcing hundreds of families to flee their makeshift homes and head for the city centre.
The AU force, which already controls most of the capital, is trying to advance through the Afgoye corridor, once a rural area northwest of Mogadishu but now home to hundreds of thousands of Somalis uprooted from their homes.
The corridor, believed to house the largest concentration of internally displaced people in the world, stretches some 30 km northwest of Mogadishu to the al Shabaab stronghold of Afgoye.
The AU force began its advance on Tuesday and seized part of Tre Disho village, 13 km from the capital.
"They have successfully captured some new territories towards Afgoye, and we are hopeful in the next 24 hours or 48 hours we will definitely capture Afgoye and even go further," Somali Defence Minister Hussein Arab Essa said in Addis Ababa.
"The targets are to make sure that we connect all regions of Somalia. That operation is actually on target," he told Reuters.
Burundian troops with the African Union Mission in Somalia (AMISOM) were advancing from Tre Disho towards Elasha and Afgoye on Wednesday but were meeting resistance from al Qaeda-linked al Shabaab rebels, their spokesman Captain Ndayiragije Come said.
"We want to capture Elasha and if not delayed by resistance we shall capture Afgoye. We captured two anti-aircraft guns hooked on cars and destroyed one yesterday. We also see about 40 bloated dead bodies of al Shabaab lying under the shrubs. They were killed in yesterday's battle," he said.
Al Shabaab has waged a bloody five-year campaign to topple Somalia's Western-backed government and impose its harsh interpretation of sharia, Islamic law, on a country that has been mired in violence for the last two decades.
It still controls swathes of central and southern Somalia but is being gradually squeezed out of its strongholds by Kenyan and Ethiopian troops who have launched their own incursions into Somalia, and is being pushed out of Mogadishu by AU forces.
Al Shabaab said they had lost four fighters and killed three AU soldiers, which Come said was untrue. On Tuesday they said they had killed 30 soldiers. It is difficult to verify either side's estimates of casualties, which are often exaggerated.
"Our enemies are again preparing for more battles but we are ready," Sheikh Abdiasis Abu Musab, the spokesman for al Shabaab's military operations, told Reuters.
Civilians fleeing the fighting hoped to find safety in central Mogadishu. "We fled with the children early in the morning," Farhia Aden, a mother of two, told Reuters in Bakara market. "We couldn't stay there because shells were landing and bullets were buzzing around us."
The U.N. Resident and Humanitarian Coordinator for Somali said prolonged fighting could displace more people.
"I remain concerned that an escalation of hostilities or a prolonged operation could lead to displacement, further straining the capacity of settlements and host communities in Mogadishu or driving people away from the life-saving help they require," Mark Bowden said in a statement.
One resident, Hussein Farah, said he had seen many rebels aboard vehicles, some with machineguns on their shoulders.
"It may take time for the government to control that area," he said at the Ex-Control checkpoint where Somali soldiers stopped his family from entering the capital.
Somali police officer Capt. Ahmed Nour said government forces had blocked the road because they did not want civilians to get caught in the shooting.
"There is military movement along the road. Many families have already come in and we shall give access to the remaining ones later when we reopen the checkpoint," he said.
AMISOM says that securing the Afgoye corridor would enable aid to reach some 400,000 people. In a statement on Wednesday it encouraged people to stay at home and said its troops were avoiding heavily residential areas near Afgoye's main road.
A Reuters witness, at an airstrip in Mogadishu where the offensive was launched, said he had seen two dead Somali soldiers and two wounded Burundian ones on Tuesday.
(Additional reporting by Aaron Maasho in Addis Ababa; Writing by Yara Bayoumy; Editing by George Obulutsa and Tim Pearce)