A DIESEL shortage in the Zambian capital Lusaka has worsened, forcing some motorists to spend nights at filling stations while some bus operators have had to reschedule their departure times. A check around Lusaka on Wednesday found most filling stations only selling a maximum of 100 litres for any vehicle, litres which bus operators felt were too little for their long journeys. But Energy deputy minister Celestino Chibamba, described the ongoing shortage as artificial and attributed it to dealers hoarding the commodity.