President Bush has backed away from an initial claim the Iranian government is directly responsible for sophisticated roadside bombs killing U.S. troops in Iraq. At a news conference Wednesday, the president said he stills believes the bombs are coming from Iran, but admitted he did not know if the Iranian government was directly involved.

President Bush: “What we do know is that the Quds Force was instrumental in providing these deadly IEDs to networks inside of Iraq. We know that. And we also know that the Quds Force is a part of the Iranian government. That’s a known. What we don’t know is whether or not the head leaders of Iran ordered the Quds Force to do what they did. But here’s my point: Either they knew or didn’t know. And what matters is that they’re there. What’s worse, that the government knew or that the government didn’t know?”

The president’s comments follow days of apparent confusion over the administration’s stance. Pentagon officials initially claimed the weapons shipments were being directed at the highest levels of the Iranian government. But just one day later top U.S. military leader General Peter Pace admitted he did not know if the Iranian government was involved. Several analysts have also questioned the claim the bombs are coming from Iran to begin with. Most bombing attacks against U.S. troops are believed to come from the same Sunni groups that the Iranian government opposes.