MOGADISHU — At least 18 people have been killed in gun battles in southern Somalia's Kismayu, residents said on Saturday, in the heaviest fighting the disputed port city has seen in more than four years. The clashes, the first since several former warlords staked rival claims on the lucrative port and fertile hinterlands in May, has stoked fears among locals of a return to the clan wars that tipped the country into anarchy two decades ago. Residents counted at least 13 bodies, nearly all militiamen, in the sandy streets of two neighborhoods which witnessed the brunt of Saturday's fighting. Five people were killed a day earlier when the clashes first broke out. “The Ras Kamboni militia now controls this part of the city,” Bile Nur, a resident of Kismayu's Calanleey district told Reuters by telephone. “Residents are burying the dead of the militia driven out while Ras Kamboni are burying theirs.” Earlier residents hid indoors as fighters riding in machine gun-mounted pick-up trucks battled for territorial control. Businesses remained shut and the streets of Somalia's second biggest city were empty of civilians as mortar blasts rang out. Kismayu was controlled by militant group Al-Shabab until last September when the militants fled an offensive by Kenyan troops supported by Ras Kamboni, a militia group loyal to a former governor of Kismayu, Ahmed Madobe. A local assembly last month declared Madobe president of the southern Jubaland region, handing him back control of Kismayu. But Somalia's central government, which does not view Madobe favorably, said his appointment was unconstitutional. Within days, three other men had pronounced themselves president, including Barre Hirale, a pro-Mogadishu former defense minister. Fighting broke out when Madobe's fighters stopped another of the claimants from visiting a hotel were Somalia's defense minister and other officials were meeting. Regional capitals and Western donors are nervous of any reversal of security gains made in Somalia by African Union peacekeepers in the fight against the Al-Qaeda-linked militants, seen as a threat to stability in east Africa and beyond. How the fate of Kismayu and the Jubaland region is resolved is a litmus test for Somalia as it rebuilds from the ruins of war and cements a fragile peace. Mogadishu insists there is no going back to civil war, but government-led talks on Kismayu are being stymied by the divisive clan politics that dog Somalia. Many residents weary of years of turmoil hold little hope for a negotiated end. Madobe's apparently close relationship with the Kenyan military has raised tensions between the Mogadishu and Nairobi governments. A Kenyan ally in southern Somalia could provide Nairobi with a welcome buffer along their porous border. On Saturday, Somalia's President Hassan Sheikh Mohamud returned to Mogadishu after talks with Kenya's new leader. The pair have met at least five times since Uhuru Kenyatta's inauguration in early April, aides say. Al-Shabab blamed Kenya for the latest violence. “The Kenyan government will be held fully responsible for every drop of blood,” Sheikh Xudayfa Abdirahman, a senior Al-Shabab official, told Reuters. Al-Shabab wants to impose a strict version of Islamic law on Somalia and has been blamed for many attacks on Kenyan soil. — Reuters