Swarms of locusts have descended on Cameroon's arid Far North province, exacerbating fears of food shortages in a region where low rainfall has already hit crop yields, officials said on Friday. "Migratory locusts have invaded all the six divisions of the Far North," a statement from Agriculture and Rural Development Minister Clobert Tchatat said. He gave no further details. Radio reports from the region, which is squeezed between Nigeria to the west and Chad to the east, said locusts darkened the skies and ate any green leaves they could find. Last year, locusts munched their way across swathes of West Africa in the worst infestation in 15 years. The invasion raised fears of famine in a region where many are subsistence farmers. Arid, semi-desert Niger and Mauritania were among the hardest hit. On Thursday, the United Nations said drought and the locust infestation had left 3.6 million people in critical need of food aid in Niger, Reuters reported. Cameroon, which stretches from mangrove swamps on the Atlantic Coast to the more arid north by Lake Chad, was not affected by last year's plague.