Last fall, the ICC gave prosecutors authority to probe alleged human rights abuses in the Ivory Coast after the disputed 2010 election. Former President Laurent Gbagbo refused to leave office after losing a U.N.-certified election to Alassane Quattara plunging the country into months of violence.
Gbagbo was captured by Ivorian forces last April and was transferred to ICC custody in November.
Three judges serving in a pre-trial chamber at the international court in The Hague Wednesday expanded the investigation to cover any crimes or atrocities possibly committed between Sept. 19, 2002 -- the start of the country's civil war -- and Nov. 28, 2010, the date of the presidential election.
"Concentrating on the most significant of the samples of incidents, the chamber concluded that there is reasonable basis to believe that, in the course of these events, acts of murder and rape that could amount to war crimes or crimes against humanity were committed," the ICC said in a release.