Expressing serious concerns over illegal flow of ammonium nitrate’a key ingredient of IEDs being used by terrorists in Afghanistan–Pakistan region, US Senators have asked the Obama Administration to ensure that Islamabad takes appropriate step in this regard. Speaking at a Congressional hearing, Senator Tom Casey said the US needs to work more closely with Pakistan to insure that ammonium nitrate did not flow across the border to Afghanistan.Appearing before the Congressional Committee, Senior Economic Advisor to the Special Representative to Afghanistan and Pakistan, Mary Beth Goodman said, the IEDs were responsible for a vast majority of coalition fatalities and injuries. She said these were also the cause of significant civilian deaths among Pakistani and Afghan citizens.