At least 554 fighters, including some civilians, were killed in Syria's predominantly Kurdish city of Kobane since the battles erupted between the Islamic State (IS) militants and the Kurdish People's Protection Units (YPG) three weeks ago, the oppositional Syrian Observatory for Human Rights reported on Saturday.
The death toll includes 20 Kurdish civilians, 226 YPG and other affiliated Kurdish fighters, as well as 298 IS members, said the Observatory, adding that the death toll could be even higher.
Amid ongoing battles in the southern part of Kobane, two big explosions rocked its southwestern part on Saturday, said the Observatory, adding that the explosions couldn't be confirmed yet.
The Observatory said earlier that the IS fighters had captured over 40 percent of Kobane, adding that Saturday's fighting were in several areas in the strategic city on the borders with Turkey.
The capture of the city would enable the IS to link its self- declared capital of al-Raqqa province with Kobane and stretch its territory to areas bordering Turkey.
Syrian government officials and Kurdish activists accused Turkey of aiding the IS into capturing Kobane to eliminate the Kurdish presence in that area and impose the long-desired buffer zone protected by a no-fly zone in northern Syria.
The IS has captured more than 300 villages around Kobane, and force over 160,000 people to flee towards neighboring Turkey since it unleashed its attacks on Sept. 16.