Warplanes from the US-led coalition battling the Islamic State group hit dozens of jihadist vehicles and bases, including an "electronic warfare garrison," in four days of strikes, the US military said Monday.

Between November 28 and December 1, coalition aircraft and drones bombed targets in Iraq and Syria, where they hit militants besieging the town of Kobane and IS headquarters in Raqa.

In Raqa, they struck a tank, 14 other vehicles, a jihadist base and what they described as an electronic warfare garrison and a separate "jamming system," US Central Command said.

Kobane, on Syria's northern border with Turkey, is in the grip of an intense battle between Kurdish militia fighters and IS jihadists.

This was the scene of 17 of the 27 strikes conducted in Syria over the four-day reporting period, and the US military said seven IS units, two buildings, three tanks and four vehicles were hit.

Separately, a strike targeted the so-called "Khorasan Group," a network of veteran Al-Qaeda operatives, near Aleppo. No damage report or casualty estimate was given for this strike.

In Iraq, a further 28 strikes hit IS vehicles, artillery, bases and fighting positions near the towns of Mosul, Hit, Tal Afar, Tikrit and Ramadi.

In Syria, the US-led campaign is supported by planes and pilots from Bahrain, Jordan, Saudi Arabia, and the United Arab Emirates.

In Iraq, the coalition is joined by Australia, Belgium, Britain, Canada, Denmark, France and the Netherlands.

The strikes began in Iraq in August after the Islamic State group captured Mosul and launched a lightning offensive that seized swathes of the country's western desert, threating the approaches to Baghdad.

The campaign was later extended to Syria after President Barack Obama vowed to "degrade and ultimately destroy" the IS threat through strikes and increased support for Iraqi and Kurdish forces.