Iraqi forces say they have cleared Islamic State (IS) militants from a wide area around the strategic Haditha dam, helped by US air strikes.
The jihadists have repeatedly tried to capture the dam in western Anbar province from government troops and their Sunni militia allies.
The action marked a widening of US air strikes which have previously been in support of Kurdish forces in the north.
US President Barack Obama is to reveal a strategy on Wednesday to defeat IS.
The leader of a pro-Iraqi government paramilitary force in western Iraq said the air strikes wiped out an IS patrol trying to attack the dam.
“They (the air strikes) were very accurate. There was no collateral damage. If Islamic State had gained control of the dam, many areas of Iraq would have been seriously threatened, even (the capital) Baghdad,” Sheik Ahmed Abu Risha told Reuters.
Iraqi forces then launched a drive against militants in the Haditha area and regained ground.
“Joint forces backed by air support and tribesmen launched a wide attack to clear the areas surrounding the Haditha district,” security spokesman Lt Gen Qassem Atta told AFP news agency.
Troops and militia also retook Barwana, east of Haditha, from IS fighters, who abandoned their weapons and vehicles in their retreat, AFP reported.
However, the governor of Anbar, Ahmed al-Dulaimi, was wounded by a mortar round shortly after Barwana was retaken.
The US military said it carried out five strikes involving bomber and fighter aircraft.
It said militants’ armoured vehicles – some carrying anti-aircraft artillery – were destroyed. The US said all its aircraft left the area safely.
Haditha dam is Iraq’s second biggest hydroelectric facility and also provides millions with water.
The US has carried out more than 130 air strikes since early August to support Iraqi and Kurdish forces fighting IS in northern Iraq, but Sunday’s strikes were the first in Anbar.
‘Nature of threat’
Mr Obama, who has been criticised for failing to outline a strategy, told NBC TV the US would weaken IS, shrink its territory and “defeat them”.
He said the strategy was “not going to be an announcement about US ground troops”.
“This is not the equivalent of the Iraq war. This… is similar to the kinds of counterterrorism campaigns that we’ve been engaging in consistently over the last five, six, seven years.
“I just want the American people to understand the nature of the threat and how we’re going to deal with it and to have confidence that we’ll be able to deal with it.”
He said the strategy would involve an international coalition.
Islamic State fighters have targeted a number of dams in their offensive, capturing the facility at Fallujah.
They also took the largest dam, at Mosul, but US air strikes helped force them out.
IS, also referred to as Isil or Isis, has taken over large swathes of Iraq and Syria in recent months, declaring the land it controls a “caliphate”.