A Nigerian man was burned to death by a mob in the capital Abuja on Saturday following an argument with a Muslim cleric, police said. Josephine Adeh, police spokesperson for Abuja, said Ahmad Usman had an argument with an unidentified cleric, which turned violent. Police who arrived at the scene took him to the hospital where he was declared dead on arrival. “The heated argument degenerated into an outbreak of violence that led to the murder and setting ablaze of Ahmad Usman by the enraged mob mobilized by the clergy numbering about two hundred,” the police spokesman for Abuja said. Last month…