NEAR MOSUL DAM, Iraq (Reuters) - Kurdish forces in northern Iraq said on Wednesday they had cleared Islamic State insurgents from nearly 500 square kilometers of territory and broken a key IS supply line between the city of Mosul and strongholds to the west near Syria.
An al Qaeda splinter group, Islamic State took Mosul, the biggest northern city, and wide swathes of northern and western Iraq in June, humbling weak government forces. But regional Kurdish peshmerga forces have since regained considerable ground with the help of U.S.-led air strikes on Islamic State.
Assisted by air strikes that began the night before and continued during the ground attack, peshmerga fighters advanced from five directions and took a commanding position above a critical crossroads at Kiske, 40 km (25 miles) west of Mosul.
A fleet of bulldozers followed, building berms and digging trenches to secure their gains.
If the Kurds manage to keep the route blocked, it would help isolate Mosul from the city of Tal Afar, an IS bastion 70 km to the west, and the Syrian border another 100 km further west. Islamic State also controls much of eastern Syria.
Masrour Barzani, head of the Kurdish Security Council, told a news conference that Islamic State fighters could still travel between Mosul and Tal Afar but said it would take longer and make communications more difficult.
“Mosul is more isolated from north, east and south than it was before. There is more heat on ISIS,” he said at an operations center, using another acronym for Islamic State.
The Kurds recaptured the Rabia border crossing with Syria, astride the main highway to Mosul, in September and last month rescued hundreds of minority Yazidis trapped by Islamic State on Sinjar Mountain.
However, confronted with Iraq’s long border with Syria, the Kurds have struggled to deal Islamic State a decisive blow to overcome their remaining outposts in northwestern Iraq.
Barzani said the bodies of at least 200 IS insurgents were found during Wednesday’s offensive; he declined to say how many peshmerga fighters were killed.
He said Islamic State had sent 14 car bombs to front lines for attacks but they were destroyed en route by air strikes or anti-tank missiles. Barzani added that some fighting continued in the region on Wednesday night.
A Reuters correspondent on one front saw through binoculars the black flag of Islamic State flying from a pylon near the village of Hassan Jallad, 25 km northwest of Mosul.
Moments later a puff of grey smoke followed what the peshmerga said was an anti-tank missile hitting an IS suicide bomber approaching the village. Though IS responded with mortars of its own, one Kurdish fighter said ground attacks and coalition air strikes had weakened the radical jihadist group.
“They are not as strong as they used to be,” he said.
Reporting by Isabel Coles; Writing by Stephen Kalin; Editing by Mark Heinrich