Baghdad: Violence is down 55 per cent in Iraq since the US troop buildup early this summer, but it is unclear what role Iran played in the downturn, US officials said today.

Washington has accused Iran of training, arming and funding Shiite extremists inside Iraq. In recent weeks, US officials have said Tehran appears to have halted the flow of arms across its border into Iraq. But US officials said today that it was too early to determine Iran's role in a recent sharp downturn in violence.

"It's unclear to us what role the Iranians might have had in these developments, if any," said Philip T Reeker, spokesman for the US Embassy in Baghdad. "It's difficult to read trends in reductions. You have to ask questions about what may be behind that," he said at a news conference in Baghdad's US-guarded Green Zone.

Overall attacks in Iraq have fallen 55 per cent since nearly 30,000 additional US reinforcements arrived in Iraq by June, said Rear Adm Gregory Smith, a US military spokesman. Some areas are at their lowest levels of violence since the summer of 2005, he said. "Make no doubt... Iran has been the principle supplier of weapons, arms, training and funding of many militia groups," Smith told reporters. "That has not changed."

"A large number of Iranian weapons still exist here in Iraq. We do believe there are still individuals who are coordinating activities... The degree to which Iran has ceased completely its training, equipping, financing and resourcing has yet to be witnessed or determined on the battlefield, but the trends are going in the right direction," Smith said.

Source : PTI