The prosecutor of the International Criminal Court said on Thursday he was investigating last month's deadly crackdown on opponents of Guinea's military ruler, Captain Moussa Dadis Camara.
At least 157 people were killed and 1,200 injured on September 28 when security forces in the West African nation attacked tens of thousands of protesters calling for Camara to step down.
It was the worst outbreak of violence since Camara seized control of the world's biggest bauxite-exporting nation in a December 2008 coup.
"A preliminary examination of the situation has been immediately initiated in order to determine whether crimes falling under the Court's jurisdiction have been perpetrated," the office of ICC prosecutor Luis Moreno-Ocampo said in a statement.
"From the information we have received, from the pictures I have seen, women were abused or otherwise brutalized on the pitch of Conakry's stadium, apparently by men in uniform", Deputy Prosecutor Fatou Bensouda said in a statement.
"This is appalling, unacceptable. It must never happen again. Those responsible must be held accountable."
The European Union and African Union have both warned of worst consequences if the Guinea junta leadership stands for election.
At the end of a Europe and African Union joint ministerial meeting in Addis Ababa on Thursday, both sides expressed their concern on the deteriorating security situation in Guinea and urged the military leadership to respect the rule of law.
EU commissioner for Development and Humanitarian aid Karel de Gucht called for a strong action against Guinean military rulers. Gucht said EU and AU had agreed to step up measures to prevent unconstitutional change of government in Africa.
African Union through the International Contact Group and regional bloc ECOWAS warned of possible charges against the junta leadership to face justice, including at the International Criminal Court (ICC).
In its statement, the International Contact Group for Guinea urged UN secretary general in collaboration with African Union to establish an independent inquiry to probe the recent killings and gross human right violations.
The statement also called for the inquiry to investigate and identify the culprits and prosecute them in a competent national court or International Criminal Court (ICC).
This latest African Union position is a contradiction to its recent strong anti-ICC stand in the case of Sudanese president Omar Hassan Al Bashir who has been indicted by the court. African Union officials decline to comment on the issue.
A European Union ministerial delegation spent the last three days with its African counterparts taking note on the Guinean situation.
EU announced its decision to suspend 260 million euro allocated for Guinea after a recent violence in Conakry which left hundreds dead and many injured.
African Union set a one-month deadline for Guinean leadership to confirm its withdrawal from the upcoming election.
There will be a strong agreement among African nations and Western partners to isolate Guinean junta, African Union Commission Peace and Security commissioner Ramatane Lamamra told reporters.
Lamamra said the five permanent United Nation Security Council members were also told to respect AU commission recommendation on Guinea.