Baghdad: Kurdish peshmerga fighters backed by federal forces and US warplanes pressed a counter-offensive Monday against militants after retaking Iraq's largest dam, as the United States and Britain stepped up their military involvement.
The recapture of Mosul dam marks the biggest prize yet clawed back from Islamic State (IS) militants since they launched a major offensive in northern Iraq in June, sweeping Iraqi security
US aircraft are carrying out strikes in support of the forces battling IS militants.
The militants also came under attack in their Syrian stronghold of Raqa by Syria's air force for a second straight day on Monday.
In Iraq, "the planes are striking and the peshmerga are advancing," a Kurdish fighter said on Monday near the shore of the lake formed by the vast Mosul dam.
Journalists heard jets flying overhead, and saw smoke rising from the site of a strike that a peshmerga member said targeted one of the entrances to the dam.
Fighting also broke out in an area south of the barrage while engineering teams worked to clear booby traps and bombs left by jihadists, said Kawa Khatari, an official from Iraq's main Kurdish party.
And a senior peshmerga officer said that there was sporadic fighting with militants in the town of Tal Kayf southeast of the dam, and that only a "small number" of jihadists remain in the area of the dam itself.
Iraqi security spokesman Lieutenant General Qassem Atta confirmed that Mosul dam was entirely liberated in a joint operation by Iraqi "anti-terrorism forces and peshmerga forces with aerial support".
Atta added on state television that while the dam had been retaken, fighting was continuing in adjoining facilities.
The Mosul dam breakthrough came after US warplanes and drones at the weekend carried out their heaviest-yet bombing against IS militants in the north since they began launching air strikes on August 8.
The US Central Command reported that the military had carried out 14 air strikes on Sunday near the dam located on the Tigris river, which provides electricity and irrigation water for farming to much of the region.
Sunday's strikes destroyed 10 IS armed vehicles, seven IS Humvees, two armoured personnel carriers and one IS checkpoint.
That military action followed nine US strikes near Arbil and Mosul dam on Saturday.
US President Barack Obama told Congress that the "limited" air strikes he has authorised on Iraq to support the fight for the dam protected US interests there.
Highlighting the stakes at hand, Obama said: "The failure of the Mosul dam could threaten the lives of large numbers of civilians, endanger US personnel and facilities, including the US Embassy in Baghdad, and prevent the Iraqi government from providing critical services to the Iraqi populace."
IS also faced air strikes on the Syrian side of the border, the Syrian Observatory for Human Rights said. In Raqa province, the Syrian air force on Monday carried out at least 14 raids against militants positions, a day after launching 16 strikes which killed at least 31 jihadists and eight civilians.
"The regime wants to show the Americans that it is also capable of striking the IS," said the Britain-based group's director, Rami Abdel Rahman.
British Prime Minister David Cameron described the Islamic State fighters sweeping across Syria and Iraq as a direct threat to Britain, and said all available tools must be used to halt their advance.
Cameron, writing in the Sunday Telegraph, said that while it would not be right to send an army into Iraq, some degree of military involvement was justified due to the threat that an expanding "terrorist state" would pose to Europe and its allies.
His Defence Minister Michael Fallon, in comments published Monday, said Britain's Iraq involvement now goes beyond a humanitarian mission and is set to last for months. "We and other countries in Europe are determined to help the government of Iraq combat this new and very extreme form of terrorism," he was quoted as saying.