He added: "This team of investigators is committed to conducting a thorough and impartial investigation".
The statement called for an impartial investigation into the confrontation.
"She wants to cooperate with a fair and impartial investigation.
Germany's bishops have vowed a thorough and impartial investigation into the abuse.
Almost nobody thinks the state capable of conducting an impartial investigation into such matters.
"There needs to be a fair and impartial investigation into what happened," he said.
The proposal followed a call last week by the UN Security Council for an impartial investigation.
He calls for a prompt, effective and impartial investigation into today's incident," a statement said.
We want a full impartial investigation, not one by the army that used it".
"An impartial investigation is urgently needed into these killings," Amnesty International's Nigeria director, MK Ibrahim, said.
This means an impartial investigation into abuses by all parties to the conflict.
