Former Ivorian president Laurent Gbagbo

Former Ivorian president Laurent Gbagbo Thursday pleaded "not guilty" to four charges of crimes against humanity as his high-profile trial opened five years after post-election violence wracked his nation.

Gbagbo and his co-accused, former militia leader Charles Ble Goude, both denied charges of organising "a common plan" which led to "widespread" murders, rapes, persecution and other "inhumane acts" at the start of their long-awaited trial at the International Criminal Court (ICC) in The Hague.