MOGADISHU (AFP) - Gunmen killed a doctor working with a US charity and his driver in southern Somalia, officials and residents said Thursday, highlighting the continuing insecurity in the shattered nation. Mohamed Muse Ali, 40, a doctor with the International Medical Corps (IMC) was slain late Wednesday in El-Berde, about 400 kilometres (250 miles) northwest of the capital Mogadishu, they said. "He was returning to his house from office when armed men shot him," Mohamed Ahmed, an IMC officer in the nearby Hodur township, told AFP by telephone. He said Ahmed said Ali, who was buried early Thursday, might have been a victim of an inter-clan feud in the region. "We are not sure why he was killed, but I think it was retaliation for previous inter-clan feuds," he said. Residents said the gunmen also shot the driver as he tried to protect the aid worker. "Three men armed with AK 47 rifles stopped the doctor in town and one of them shot him twice. His driver, Lel Idris, was also shot by another gunman while trying to protect the doctor," said Hassan Sheik Ali, a resident. It was not immediately clear whether the driver was an IMC employee. The IMC, based in Santa Monica, California, started operations in Somalia in the 1990s. It provides a range of health and nutritional services to communities in the country's southern and central regions. Somalia has been without a functioning central authority since the 1991 ouster of dictator Mohamed Siad Barre touched off a bloody power struggle that has defied numerous attempts to restore stability. Efforts by the nearly three-year-old interim government to exert control over Mogadishu have been hindered by the near-daily insurgent attacks against its officials, Ethiopian troops and African Union peacekeepers. Much of the country of about 10 million people is awaiting the deployment of peacekeepers to help the government tighten its tenuous grip across the country as well as protect relief wor