(IDEX Online) - Botswana has introduced a night-time curfew in an attempt to avoid what has been described as an "impending catastrophe".The world's biggest supplier of diamonds has seen exports fall by over 40 per cent during the pandemic. President Dr Mokgweetsi Masisi imposed a 7pm to 4am curfew from December 24 to January 3 and renewed the country's state of emergency.Botswana has closed its borders, imposed travel restrictions and brought in limited lockdowns during the pandemic, but it has not previously ordered a curfew.The death toll from coronavirus remains comparatively low - 40 fatalities among a population of 2.25m - but the country is in recession and currently does not have access to a vaccine.Dr Masisi said government's ability to raise revenue had been badly hit by the decline in key revenue areas, namely diamonds and tourism.