Patrolling Iraqi skies ... Sailors direct an aircraft, as an F/A-18E Super Hornet takes off from the flight deck of the aircraft carrier USS George H.W. Bush. Credit:AFP Prompted by the seizure of the dam by the group known as the Islamic State, along with the dire circumstances of tens of thousands of civilians stranded in the mountains near Sinjar, in northwestern Iraq, Obama quickly ordered airdrops of humanitarian aid and airstrikes on militant positions near the Kurdish capital, Irbil. As the Islamic State consolidates its control of territory, it has acted brutally, carrying out executions and forcing out minority groups. But it has also displayed an intent to act strategically when it comes to natural resources, highlighted by the call on Saturday for engineers on the dam to get back to work. The group's control over the dam, however, also gives the group the ability to create a civilian catastrophe: A break in the fragile dam could unleash a tidal wave over the city of Mosul and cause flooding and countless deaths along the Tigris River south to Baghdad and beyond, experts have said. The Islamic State order came as residents in Mosul reported that nearly two dozen bodies of Islamic State fighters, said to have been killed in the US airstrikes, arrived at the city's morgue, while at least 30 wounded fighters were being treated at a hospital.

In Baghdad, efforts by leaders to name a replacement for Prime Minister Nouri al-Maliki, a Shiite, stalled, with al-Maliki clinging to power and rivals unable to decide on an alternative. A session of Parliament scheduled for Sunday - when leaders had been expected to nominate a new prime minister - was postponed until Monday, as some Shiite leaders rushed to Iran, which holds enormous power in Iraq, and Sunni politicians visited Irbil to confer with the Kurds. "Until this moment, nothing has changed," said Kamal al-Saadi, a member of Parliament from al-Maliki's bloc. "We are sticking with our only candidate, Maliki." Earlier, Obama had suggested that wider US military support, including an expansion of the airstrikes, could come if Iraqi leaders formed a national unity government with meaningful roles for the country's two main minority groups, Sunnis and Kurds. Without saying so explicitly, US officials have been quietly working to replace al-Maliki because they believe that he is incapable of uniting the country to face the militant threat. On Saturday, Obama said that an inclusive Iraqi government would give all Iraqis a reason to believe they were represented and help give Iraqi military forces a reason to fight back against the militants. His announcement prompted immediate criticism from Senator John McCain, who said in an interview by telephone from Vietnam that the president's vision for the campaign was insufficient to fight "the richest, most powerful terrorist organisation in history."

The US continued on Saturday its efforts to address the crisis in Iraq, as three US military cargo planes, escorted by Navy F-18 fighter jets, dropped more food and water on Mount Sinjar to help refugees who had fled there under threat from the Sunni militants. The humanitarian assistance came after a day of military strikes by Navy warplanes and Predator drones on Islamic State artillery positions. The planes - one C-17 and two C-130s - dropped more than 28,000 ready-to-eat meals and more than 1,500 gallons of fresh drinking water, the Pentagon said. That brought to 36,224 the number of meals delivered to the refugees in the last two days. In London, Britain's foreign secretary, Philip Hammond, said in a statement on television that Royal Air Force planes would begin humanitarian airdrops in northern Iraq "imminently." Britain had announced Friday that it would support the US relief effort there but would avoid military action. Britain was a close ally of the United States in the 2003 invasion of Iraq, and in operations in Afghanistan, but its appetite for overseas military deployments has faded. Last year, Parliament refused to authorise military action in Syria in response to the use of chemical weapons in the civil war there. The Islamic State's advance northward over the last week appeared to reflect a shift in strategy, as the group had previously said it planned to march on Baghdad. That was stalled when Shiite militias quickly mobilised to defend the capital.

While the Islamic State has been the most prominent fighting force of the Sunni insurgency in Iraq, its gains could not have come without the support of other Sunni groups, experts say. Those groups include fighters aligned with Saddam Hussein's Baath Party, which is not sympathetic to the religious extremism of the Islamic State but is seen as more intent on taking the fight to Baghdad and trying to topple the central government. In a recent statement, the Iraqi Baath Party condemned the Islamic State's attacks on the Kurdish region, suggesting emerging fissures in the alliance of Sunni resistance. "We categorically reject the fight against Kurdistan," the statement said. "Kurdistan and its government were a safe haven to all Iraqis." The statement added, "We call on all military brigades to move on Baghdad instead." As the Islamic State went to work securing the Mosul Dam on Saturday, its fighters appeared to make progress in a battle for control of the Haditha Dam, Iraq's second-largest, which sits on the Euphrates River farther south in Anbar province. Security forces said militants had destroyed a strategic bridge near the town of Barwana, which government forces had been using to resupply fighting units. Within Islamic State-controlled territory, the new US involvement in Iraq has provided a rallying cry. With the Islamic State leader, Abu Bakr al-Baghdadi, who has declared areas under his control in Iraq and Syria a new Islamic caliphate, calling for jihad against the United States, imams have called on citizens to fight the United States.

Loading One preacher in Fallujah, which has been under Islamic State control since the end of last year, said at Friday prayers: "We know there comes a day to fight the United States. We are ready to march towards Irbil and Baghdad. The Islamic State will not be defeated and we are willing to keep pursuing jihad, according to the plans." New York Times