BAGHDAD: France mounted its first air strike to beat back the Islamic State group in Iraq on Friday, even as militants across the border in Syria seized dozens of Kurdish villages in a lightning offensive.

More than a decade after Paris famously refused to back the US-led invasion of Iraq, France became the first nation to join America's campaign of air strikes targeting the Islamic State (IS) in the war-torn country.

“This morning at 9:40, our Rafale planes carried out a first strike against a logistics depot of the terrorist organisation,” President Francois Hollande said.

French defence ministry sources said two jets dropped laser-guided GBU-12 bombs in the Mosul area. They said “a lot of ammunition”, vehicles and fuel reserves were destroyed.

Kurdish military spokesman Halgord Hekmat identified the location as Tal Mus, between the city of Mosul and Zumar.

France, as well as Britain, had already sent aircraft into Iraq's skies for surveillance missions.

US aircraft have carried out 178 strikes since August 8 but President Barack Obama has been keen to build a broad international coalition.

At the United Nations Security Council in New York, US Secretary of State John Kerry brought together 35 countries — including Washington's traditional foe Iran, to bolster support for the campaign against the militants.

Kerry said the turnout, which also included Britain, Turkey, Saudi Arabia and Qatar, showed “the clear need for all of us to come together, to welcome and to support the new inclusive government in Iraq and of course to put an end to ISIL's unfettered barbarity”.

Tehran is backing both Iraq and Syria in their battle against the Islamic State group, and Kerry said that in combating the militant threat “there is a role for nearly every country to play, including Iran”.

Congress support

The latest confirmed strikes came when a boat resupplying US fighters and a militant ground unit were destroyed southeast and southwest of Baghdad, respectively.

The bombing campaign was launched to protect Iraqi Kurdistan from advancing militants and to help the autonomous region's troops retake the ground they lost.

Militants who had already controlled large swathes of land in Syria led a militant offensive that took the city of Mosul, Iraq's second largest, on June 10 and then swept through much of the Sunni heartland.

In a second push in August, they dealt Iraq's Kurdish peshmerga forces a string of military defeats and attacked various minority groups, demolished heritage sites and displaced hundreds of thousands of people.

Footage of the beheading of two US journalists and a British aid worker in Syria have since sparked international outrage and spurred calls for tougher action against IS.

But Obama has vowed not to put “boots on the ground”, fearful of dragging US forces back into the Iraqi quagmire only three years after pulling them out.

The US leader has instead pledged to support Kurdish and Iraqi federal forces by offering air support and arms, as well as targeting intelligence and training.

On Thursday, Congress backed his plan to arm Syrian rebels to take on IS in conjunction with air strikes, which Obama has pledged to carry out inside Syria but not yet launched.

On Friday, the Syrian Observatory for Human Rights said IS fighters had seized 60 Kurdish villages near the Turkish border in a two-day offensive using heavy weaponry.

“In the past 48 hours, they have taken 60 villages, 40 on Friday alone, “said the monitoring group's director Rami Abdel Rahman, referring to the operation around the Kurdish town of Ain al Arab.

“The Kurdish fighters are beating a retreat because they are outnumbered, “he said, as the IS closes in on Ain al Arab, which the Kurds call Kobane, on the Turkish border.

The town is one of three Kurdish majority areas where nationalists have proclaimed self-rule and its capture would give the militants control of a long stretch of the Turkish border.

Ankara reopened the frontier Friday to fleeing Kurds, saying a worst-case scenario could drive as many as 100,000 more refugees into the country.

Syria's exiled opposition National Coalition has warned of “the danger of a massacre” in the area, where Kurdish militia have doggedly resisted the militants.

Baghdad bombs

Across the border in Iraq, as security forces and militia, backed by expanding air strikes, battled to regain ground from IS and allied groups, Baghdad was rocked by a series of bombings.

In a Shia-dominated area of northern Baghdad, militants blew up two car bombs and lobbed mortar rounds late Thursday, killing at least 28 people in what some said was an attempt to target an army intelligence base where senior IS members are held.

Three bombings in and near the capital on Friday killed at least 14 people, while a fourth in the northern city of Kirkuk killed eight more, officials said.

The IS, meanwhile, hitting back in the propaganda war, posted its latest video of a Western hostage, British journalist John Cantlie, in an orange jumpsuit.