US-led aircraft hammered Islamic State militants in northern Iraq over the past 24 hours, the American military said Thursday, as Kurdish forces pressed an offensive against the jihadists in the area.

US and coalition bombers, fighter jets and drones carried out a total of 31 air raids since Wednesday morning, including ten in Syria and 21 in Iraq, according to the American military command overseeing "Operation Inherent Resolve" out of headquarters in Kuwait.

The raids coincided with a ground offensive by Kurdish forces against the IS group, with Kurdish officials claiming they had cut a key road linking the IS stronghold of Mosul with Tal Afar to the west.

Near Mosul, coalition planes struck IS units, buildings, a mortar team, six culverts, two bridges, artillery, a vehicle outfitted with a homemade bomb, heavy weapons and four armored vehicles, the command said. Allied warplanes also carried out two strikes near Tal Afar, two near Sinjar and one near Kirkuk.

In Syria, US and coalition aircraft conducted one strike near Raqqa and nine strikes near the Turkish border town of Kobane, which the IS group has been unable to capture despite a months-long offensive.

US commanders say the air war -- launched in August in Iraq and in September in Syria -- has halted the advance of the IS group in Iraq, hampered its movement, undercut its oil smuggling and jeopardized its supply lines. However, the jihadists remain in control of a large stretch of territory across Syria and Iraq and continue to recruit new fighters.