Afghanistan's defense minister is disputing statements by U.S. officials who say there is evidence that Iran is supplying arms to Taleban militants in Afghanistan.
In an interview with the Associated Press Thursday, Abdul Rahim Wardak said that it is "difficult to link" the Taleban's weapons to Iran.
He said al-Qaida or members of organized crime groups might be arming the Taleban.
On Wednesday, U.S. Secretary of Defense Robert Gates said Tehran must be aware that Iranian-made weapons are being shipped to insurgents in Afghanistan.
Gates also said the flow of weapons is "substantial."
On Tuesday, U.S. Undersecretary of State Nicholas Burns said there was irrefutable evidence that Tehran is shipping arms into Afghanistan.
Tehran has denied the allegations.
Gates has said he is puzzled by Tehran's intentions, because the Afghan and Iranian governments are on good terms.
Afghan President Hamid Karzai has said there is no proof of Iranian involvement in arming the Taleban.
Some information for this report was provided by AFP, AP and Reuters.