NIGERIA'S fuel tanker drivers began a strike over rising operational costs due to the recent second devaluation of the naira currency within a year and over the state of the country's roads, a union official said. The Nigerian Association of Road Transport Owners (NARTO), which groups thousands of truck owners and drivers responsible for fuel distribution in Africa's most populous nation, are pushing for higher freight charges from fuel marketers due to rising costs. Africa's biggest economy is grappling with a cost of living crisis, with the inflation rate hitting almost 30% in January - the highest in nearly three…