US forces and their allies carried out 39 air strikes on Islamic State forces in Iraq and Syria over the past two days, the Combined Joint Task Force said.
The strikes, carried out by fighters, bombers and remote-controlled aircraft hit 19 targets in the vicinity of Kobane, and 20 in Iraq, Reuters reported.
Simultaneously, in Syria, president Bashar al-Assad's government intensified air strikes on al-Bab, a northern city under control of IS militants.
According to locals, helicopters and war planes dropped barrel bombs - steel drums full of shrapnel and explosives - on residential and industrial areas in and neighbouring Qabaseen, north-east of Aleppo, on Thursday and overnight.
According to residents and the Syrian Observatory for Human Rights, at least 45 civilians were killed and about 175 wounded.
The strikes on al Bab were not reported in the Syrian state media. The city of about 100,000 people had been a target of heavy government strikes since the start of the US- led military campaign.
According to the observatory, at least 110 civilians had been killed in over 470 air strikes by Syrian government forces on rebel-held areas in Syria in the past 72 hours.
Meanwhile, The Washington Post reported that about 1.7 million Iraqis fled their homes for other parts of the country from 2006 to 2008, the worst days of sectarian conflict after the US-led invasion of 2003. Most had yet not returned to their homes.
Also, the war in neighboring Syria had left 3.2 million homeless, with some of them seeking shelter in Iraq.
The latest Iraqi crisis had stunned communities, international humanitarian organisations and the Iraqi government due to the sheer scale and speed with which it had developed.
The Iraqi government lacks the means to help the displaced millions as it fights a war against Islamist insurgents and the diving oil prices adding to its woes. To make matters worse for the displaced, the winter had set in, sending temperatures below freezing.
Almost half of the Iraqis fleeing their communities this year had crowded into Iraqi Kurdistan, already home to over 200,000 Syrian refugees.
With a scramble for survival underway, the displaced say their sects, ethnicities and whether they had crossed an international border and whether they legally qualified as refugees could determine their level of access to the scant aid available.