Iraq coordinator David M. Satterfield, who also serves as a senior adviser to U.S. Secretary of State Condoleezza Rice, said Iran has helped limit violence in Iraq by reining in the region's Shiite militants, The Washington Post reported Sunday.

Satterfield said the effect of the Iranian government's decision could be seen in a recent decrease in the number of sophisticated roadside bombings in Iraq.

The news of Iran's impact on Iraqi violence comes in the wake of a U.S. Defense Department report Wednesday that blamed Iran for impeding progress by its neighbor.

That report was followed up by comments from U.S. Defense Secretary Robert M. Gates, who said the impact Iran has had upon violence in Iraq remained unclear.

Gates said Friday that while there has been a decrease in attacks in Iraq, no country's efforts could be directly linked to the positive changes, the Post reported.