New commander takes charge as US prepares to accuse Iran

The new US military commander in Iraq warned yesterday that the country was "doomed to continued violence and civil strife" if American and Iraqi forces did not work together.

General David Petraeus took command of the 135,000-strong US force, declaring: "We will have to share the burdens and move forward together. If we can do that and if we can help the people of Iraq, the prospects of success are good. Failing that, Iraq will be doomed to continued violence and civil strife."

Standing under a crystal chandelier in one of Saddam Hussein's former palaces, General Petraeus said the task before him was "exceedingly challenging. The way ahead will be hard, and there undoubtedly will be many tough days. But as I recently told members of the US Senate, hard is not hopeless."

The Princeton-educated general takes command at a time when the Bush administration has focused on Iran as a key factor in the turmoil in Iraq.

National security officials in Washington and Iraq have worked for weeks on a presentation intended to provide evidence for the administration's claims of what they say are Iran's deadly activities. US officials in Baghdad scheduled a briefing for reporters today at which it is expected detailed evidence will be produced about Iranian involvement, linking serial numbers to explosives used by insurgents in Iraq.

Hitherto, US officials have said little about the evidence, which includes documents and items collected in raids in Iraq, to bolster such claims. Among the recovered weapons is a roadside bomb known as an "explosively formed penetrator", which can pierce the armour of Abrams tanks with nearly molten-hot charges. One intelligence official said the US is "fairly comfortable" that it knows the source of the explosives.

The Pentagon announced the death of three more US soldiers in an explosion in Diyala province north-east of Baghdad. This takes the number of Americans killed in Iraq so far this month to 36.