At least 100 Islamic State terrorists have been killed in the Kurdish city of Kobane during the past three days alone, according to a Syrian monitoring group.
The Syrian Observatory for Human Rights said the deaths brought the number of ISIS fighters killed in the fighting for the city, located along the border with Turkey in northern Syria, to 576 since the start of the jihadi offensive on September 16.
"Over the last three days, at least 100 members of ISIS and its religious police have been killed... in Kobani and its surroundings," the Observatory said in a statement Saturday.
Those killed were reportedly reinforcements brought from Aleppo and ISIS's de-facto capital Raqqa, as the group's offensive has floundered in the face of dogged Kurdish resistance, aided by US airstrikes.
Also on Friday, the Observatory said 15 fighters from the Kurdish People's Protection Units (YPG) were killed in clashes with ISIS jihadis, while at least 11 ISIS fighters were killed in US-led coalition airstrikes on Kobane and Raqqa.
958 people in total have been killed in the battle for Kobane, according to the London-based Observatory: 576 of whom belonged to ISIS and 361 belonging to the YPG and its Free Syrian Army allies. 21 civilians were also among the dead.
It is hoped that the arrival of Iraqi Peshmerga forces - who crossed into Kobane from Turkey on Friday, armed with heavy weapons - will help defenders push back ISIS from around the city entirely.
Continued US airstrikes come despite growing discomfort and even infighting within the Obama administration over the White House's overall strategy in Iraq and Syria.
Secretary of Defense Chuck Hagel admitted to reporters Thursday that Syrian president Bashar al-Assad "derives some benefit" from strikes against ISIS, which are allowing regime forces to focus their firepower on other rebel groups.
Hagel has emerged as a leading critic of President Obama's Syria strategy; CNN recently revealed he sent a detailed memo to National Security Advisor Susan Rice "expressing concern about overall Syria strategy."
ISIS has been fighting both the regime and other rebel forces, and most opposition factions are in favor of strikes on the group as well, and there is wide support for airstrikes to help aid embattled Kurdish forces fend off a potential massacre by the Islamists. But there are concerns the ongoing airstrikes against ISIS are working in the regime's favor
In a report for the Center for Strategic and International Studies, regional security expert Anthony H. Cordesman described the results of the operation against ISIS as "a strategic mess."
"The Assad forces are using the U.S. and allied campaign against the Islamic State to make a massive step up in air attacks on other rebels," he wrote.