Since it was launched last September, the U.S. led air strikes against militants in Syria has killed 553 of ISIS militant, as reported Syria’s HAM monitors based in the United Kingdom.
SOHR, said details of the dead it was 464 troops of ISIS, 57 other militants and 32 civilians.
Earlier, a UN fact-finding report on the alleged actions of various war crimes perpetrated by ISIS in Iraq.
Meanwhile, fierce fighting again erupted in the town of Kobani, between the forces of ISIS that attempted to capture the city by Kurdish forces who fought to defend it.
The Kurdish source told the BBC Arabic, that ISIS managed to recapture a strategic hilltop, located four miles west of Kobani.
Kurdish forces take over the Tal Shair of ISIS, in last October 14, 2014.
The report also mentions, the troops stormed the Kurdish position ISIS and attacked the center of the city.
Some time earlier, it was reported that ISIS captured a military base and a number of fighter aircraft by using the former air force pilot during Saddam Hussein’s era to train the militants of ISIS.
To the BBC, Syria, Kurdish sources said that troops launched an attack-intensive ISIS on Wednesday October 23, 2014 from South and East of the city, in an attempt to get into the city centre.
The observers say, was the mastery of the Tal Shair is key because those who master it will have a better chance to control the Kurdish town of Kobani in Syria, near the border with Turkey.
If capture the Kobani, ISIS will be occupying the Syria border.
Turkey confirms will not let Kobani fell into the hands of ISIS, but still refused to send troops to defend the Kobani, and only allow the Kurds to enter Iraq through Turkey Kobani.
The United States recognizes that Kobani could fall, sending the supply of weapons to Kurdish fighters by air, but acknowledged there are falling into the hands of ISIS.