* ICC prosecutor to investigate deadly Guinea crackdown
* Violence "appalling, unacceptable", statement says
* AU discusses sanctions if Camara stays in race
(Corrects spelling of Lamamra in paragraphs 13-14)
AMSTERDAM, Oct 15 (Reuters) - 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 Sept. 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 brutalised 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 violence drew international condemnation. U.S. Secretary of State Hillary Clinton said Guinea’s military rulers should quit. France said it had cut military cooperation with its former colony.
The European Union’s aid chief, Karel De Gucht, said Camara should stand trial for a "crime against humanity".
The African Union has given Camara until mid-October to confirm he will not stand in presidential elections slated for Jan. 31, warning of sanctions if he misses that deadline.
Camara has blamed uncontrollable elements within the Guinean army for the killings, saying he cannot be held responsible.
The Hague-based ICC is the world’s first permanent court set up to try individuals for genocide, war crimes and other major human rights violations.
The African Union (AU) reiterated that Camara had about 24 hours to comply with the body’s ultimatum.
"What has happened is very, very unacceptable. It’s condemnable," AU Commissioner for Peace and Security Ramtane Lamamra said, adding that the Peace and Security Council had considered the types of sanctions to be imposed.
Lamamra did not give details. The Economic Community of West African States (ECOWAS) will discuss the situation in Guinea on Saturday at a one-day meeting in the Nigerian capital Abuja.