A United Nations review has found that the U.N.-African Union joint peacekeeping mission in Darfur took an "unduly conservative" approach to publicly sharing information about crimes against civilians and peacekeepers.

U.N. Secretary-General Ban Ki-moon in a statement Wednesday said he was "deeply troubled" by the findings about the 20,300-strong peacekeeping force in western Sudan, where rebels have been fighting the government for more than a decade.

The statement said a U.N. review team looked into 16 incidents that made up allegations against the mission and found no evidence to support the allegations. But "in five of the cases examined, the mission did not provide U.N. headquarters with full reports on the circumstances surrounding these incidents, which involved possible wrongdoing by government or pro-Government forces," the statement says.

It said Ban will take "all necessary steps to ensure full and accurate reporting."

The Security Council early this year ordered a review of the sprawling mission in Darfur after criticisms over its effectiveness. Then in April, a former spokeswoman for the mission, Aicha Elbasri, raised allegations in an article in Foreign Policy magazine over incomplete reporting by the mission known as UNAMID.

The U.N. statement Wednesday did not lay blame and did not mention punishment.

"Keeping silent or under-reporting on incidents involving human rights violations and threats or attacks on UN peacekeepers cannot be condoned under any circumstances," it said.

Ban has sent the executive summary of the report to the Security Council, spokesman Stephane Dujarric said.

"We welcome this report," a senior peacekeeping official said. "We're committed to ensuring that UNAMID, and all peacekeeping operations, report promptly and accurately on incidents involving attacks on civilians and U.N. peacekeeping, whomever the perpetrators may be."

The official spoke on condition of anonymity because he was not authorized to comment.

The Darfur mission has the second-highest budget of all U.N. peacekeeping forces, at more than $1.3 billion a year.

The security situation in Darfur has worsened this year, with more than 300,000 people fleeing their homes.