Secretary of State Condoleezza Rice asked her Russian counterpart on Tuesday for a "serious investigation" into reports that Russian intelligence fed U.S. battle plans to Saddam Hussein, the State Department said.

Rice made the request in a telephone call to Russian Foreign Minister Sergey Lavrov, said State Department spokesman Adam Ereli. The call came four days after the Pentagon released a report citing captured Iraqi documents that described the information exchange.

"The point we're making is, this is a report we take seriously and we are asking the Russians to look into it," Ereli said.

Even so, Defense Secretary Donald H. Rumsfeld seemed to downplay the report. He said it may be worth looking into, but said he first heard about the allegations when the Pentagon issued the publication last Friday.

"It merits looking into," Rumsfeld told Pentagon reporters.

Gen. Peter Pace, chairman of the Joint Chiefs of Staff, added that U.S. officials "still don't know if the translation is 100 percent accurate" or if the report contained "real information or disinformation."

According to the unclassified report, Russian intelligence had sources inside the American military that enabled it to feed information about U.S. troop movements to Saddam Hussein before the 2003 invasion that toppled him.

The unclassified report did not assess the value or accuracy of the information Saddam got or offer details on Russia's information pipeline.

Russian officials have said the allegations are false.