At least seven people have been killed in clashes between fighters from two communities in the Niger Delta in southern Nigeria sparked by the murder of an elderly woman, said human rights activists on Friday. Trouble started when the corpse of the woman from Mogho community in the Ogoni area of Rivers State was found in farmland on Wednesday. Mogho immediately blamed Bodo, a neighbouring community, for the woman's death. "The Mogho people set up a roadblock and started stopping people from Bodo and forcing them out of their cars. They killed one of them on Thursday," said a local activist who did not wish to be named because he has contacts among the fighters. "So today the warriors from Bodo have taken over Mogho. They have killed at least six people and they are burning down the community. It's very serious. If it doesn't stop the whole place will be destroyed," he said. "The problem is that communities in this area all have their private armouries and militias and the slightest thing can provoke violence."