In its annual report released Wednesday, the International Narcotics Control Board (INCB) said profits from cannabis and other drugs are also fueling Africa's civil wars.

The U.N. agency said conflicts in Ivory Coast, Liberia and the Central African Republic were fought with weapons bought in part with drug money.

The agency said cannabis cultivation has become a "significant economic crop" for export in West and Central Africa after the prices of agricultural products dropped in international markets.

It says cannabis cultivation in east Africa and war-torn Sudan has worsened the existing food shortage as farmers switch to the more lucrative, illicit, crop.