The US Air Force has reportedly bombed Islamic State positions near the Haditha Dam in western Iraq. 

Iraqi forces and local Sunni Arab tribesmen are currently in control of the dam, which is the second-largest in Iraq and controls the flow of the Tigris River. The airstrikes are apparently an attempt to prevent an advance on those positions by IS, which has been attempting to seize several strategically-crucial dams throughout Iraq, including Haditha. 

Last month IS took control of Mosul dam, the country's largest, but was forced out by a concerted US bombing campaign in support of a ground push by Kurdish Peshmerga forces.

The fear is that Islamists could use the dams as a weapon to flood tows and cities further downstream - as they did earlier this year after capturing the Fallujah Dam. 

The US has launched a campaign of airstrikes throughout northern Iraq in an attempt to protect "US interests" and vulnerable refugees from the Islamic State's bloody advances through the country. According to AP the American air force has conducted 133 strikes since the campaign began in early August.

Meanwhile, Canada became the latest western state to support Kurdish and Iraqi forces on the ground.

At a NATO conference Friday, Canadian Prime Minister Steven Harper said several dozen "military advisers" have been sent to northern Iraq, and that plans were force a total of between 50-100 personnel to be deployed.

“Canada is joining its allies in providing critical advice to forces in northern Iraq as they continue to hold back the terrorist advance,” Harper said.

He noted that the campaign was relatively low-risk, since Canadian soldiers would not be involved in active combat, but also acknowledged that the deployment was "not without risk."

That said, Harper insisted the risks were worth taking.

“The Canadian military and the personnel who join exist to take on reasonable risks in defence of their country’s interests and that’s what they’re doing in this situation,” he said.