Heavy fighting in the Somali capital killed at least 20 people today, the second day of fierce clashes as government forces tried to drive hardline Islamists out of their Mogadishu bases, according to Reuters. Al Qaeda-linked fighters in Somalia's al Shabaab rebel group are battling to oust President Sheikh Sharif Ahmed, himself a former Islamist insurgent who joined a peace process last year. Al Shabaab and allied fighters control much of southern and central Somalia and have boxed the government and 4,300 African Union peacekeepers into a few blocks of Mogadishu. "The streets were horrific," ambulance service official Ali Muse told Reuters. "We've transported 20 dead bodies and 55 injured in the latest fighting." Western nations and Somalia's neighbours worry that if the rebels succeed in toppling Ahmed, the Horn of Africa nation will become a safe haven for al Qaeda training camps, and hardline Islamists will destabilise the region. At an African Union summit in Libya, AU leaders discussed beefing up their force and whether to give the troops a stronger mandate to take the fight to the rebels. At present, the troops from Uganda and Burundi are largely confined to their bases and protect key sites such as the presidential palace, airport and seaport.