The United Nations agency, the Food and Agriculture Organisation, has issued a warning that the growth of huge cities in the third world is going to be accompanied by worsening food shortages.

The FAO says in its annual report that the infrastructure needed for feeding massive populations -- involving co-ordination between producers, transporters and sellers -- is not keeping up with urban expansion.

By the millenium, says the FAO, there will be twenty cities of more than ten million people -- nearly all in the third world.

The number of impoverished city dwellers will have risen from four-hundred-million in 1990 to one-billion, and there will be an anarchic spread of shanty towns, sickness, corruption and inflation.