WASHINGTON - (AP) - The top U.S. commander in Afghanistan is ordering an investigation into charges that an army unit trained in psychological operations was told improperly to manipulate American senators to get more money and troops for the war.

A senator allegedly targeted said Thursday that he is confidentthere will be a review of the facts but played down the idea thathe was manipulated.

The staff of Lt. Gen. William Caldwell, head of the effort totrain Afghan security forces, ordered the information operationsunit to compile profiles, voting records and other information onvisiting lawmakers to leverage in a campaign to get moreassistance, said a story Thursday on Rolling Stone's website. Itsays the campaign also improperly targeted the chairman of theJoint Chiefs of Staff, Adm. Mike Mullen, and others.

Caldwell's office denied that the command used an informationoperations cell to influence distinguished visitors. But a pressstatement from Kabul said the commander of forces in Afghanistan,Gen. David Petraeus, would order a probe "based on theinformation" in the article.

The episode underscores how murky the dividing line can bebetween information operations and public affairs officers, whichthe Pentagon has wrestled with in recent years as it struggled towin the hearts and minds of populations in Iraq and Afghanistan.

Pentagon spokesman Col. Dave Lapan said Thursday that the probewill look at the actions taken by Caldwell and his staff anddetermine whether they were inappropriate or illegal. Thatdistinction, he said, depends on the circumstances.

"It just depends on what it is they are doing. It's theactions, not just the assignment," said Lapan. "It all depends onhow the information is used. There is no blanket prohibitionagainst having that information provided."

As an example, he said an information operations officer couldbe asked to look up someone's biography online. He added thatPetraeus will announce who the investigating officer will be butsaid it does not necessarily have to be someone of the same orhigher rank than Caldwell.

The military cell devoted to what is known as "informationoperations" believed their mission on arriving in Afghanistan inNovember 2009 was to assess the effects of U.S. propaganda on theTaliban and local Afghan population, Rolling Stone said, quotingLt. Col. Michael Holmes, whom it identified as the leader of thefive-man team.

Holmes said they resisted the order to compile information oncongressional delegations that were visiting there and think ofwhat information "to plant inside their heads." He said they weresubjected to retaliation for resisting.

"My job in psy-ops is to play with people's heads, to get theenemy to behave the way we want them to behave," Holmes is quotedas saying. "When you ask me to try to use these skills on senatorsand congressman, you're crossing a line."

Those singled out in the campaign included Sens. John McCain, aRepublican; Independent Joe Lieberman; and Democrats Jack Reed, AlFranken and Carl Levin. Aside from senators, the story identifiedother targets as Democratic Rep. Steve Israel of the House ofRepresentatives Appropriations Committee the Czech ambassador toAfghanistan; the German interior minister, and a host ofinfluential think-tank analysts, the story said, withoutidentifying the international figures by name.

Levin pointed out Thursday that he has long been in favor ofbuilding up Afghan forces.