N"DJAMENA, Aug 16 (Reuters) - Around 11,000 people fleeing clashes between herders and fishermen in northern Cameroon arrived in neighbouring Chad at the weekend, a provincial governor in Chad said on Monday. About 20 people have been killed in what officials say is Cameroon"s worst ethnic violence in recent memory. Clashes broke out last week between fishermen and herders from different ethnic groups over a dispute about holes the fishermen dug in the ground. read more "Yesterday, our social services received nearly 11,000 refugees who came with almost nothing. They don"t have bedding, a change of clothes or food," Gayang Souare, the governor of Chari Baguirmi province in northwestern Chad, told Reuters. "There are wounded among them who require immediate medical care and children who are without their parents," he said, adding that local capacity to provide for the refugees was quickly being overwhelmed. The violence in Cameroon"s Far North region is taking place in a zone where the army has for years been battling Boko Haram and, more recently, militants linked to Islamic State. Local officials say it is the worst ethnic violence they have seen, with one of the reasons being that residents have acquired weapons in recent years in response to insecurity caused by Boko Haram and local bandits. Reporting by Mahamat Ramadane; Writing by Cooper Inveen and Aaron Ross, Editing by Timothy Heritage Our Standards: The Thomson Reuters Trust Principles.