More than 500 people, mostly Islamic militants, have been killed in U.S.-led coalition airstrikes in Syria that began last month, the Britain-based Syrian Observatory for Human Rights said Thursday, reports ABC News.

The coalition continued to aid Kurdish fighters Thursday as Islamic State forces captured the Tel Shair hill overlooking the northern Syrian border town of Kobani, which is along the Syria-Turkey border.

The Britain-based Syrian Observatory for Human Rights has tracked the number of people killed since airstrikes began Sept. 23:

  • 553 people have been killed
  • Of those killed, 32 were civilians
  • The civilians included five woman and six children
  • 464 confirmed Islamic State group deaths, though the number could be higher
  • 57 al-Qaida-linked Nusra Front fighters have died

Most of the Islamic State militant deaths resulted from the battle for Kobani, which the fighters have been attempting to capture since mid-September.

Earlier this week, the U.S. Central Command confirmed that its forces performed more than 135 airstrikes in and around Kobani, killing hundreds of militants.

"Combined with continued resistance to ISIL on the ground, indications are that these strikes have slowed ISIL advances into the city, killed hundreds of their fighters and destroyed or damaged scores of pieces of ISIL combat equipment and fighting positions," Central Command said in a statement, using an acronym for the militant group.

In northern Iraq, Fuad Hussein, the chief of staff for the Kurdistan president Massoud Barzani, told The Associated Press the fight in Kobani is very important because "we are fighting the same enemy."

According to Hussein, the Iraqi Kurdish government intends to aid Syrian Kurds by sending about 150 peshmerga fighters to Kobani through Turkey. The fighters would be armed with rocket-propelled grenades and light weapons, he added.

Capturing Kobani is of utmost importance to the Islamic State group because of the direct link between the Syrian province of Aleppo and its fortification of Raqqa.

The Islamic State group already controls a large stretch of territory along the Syria-Iraq border. They also seized dozens of Kurdish villages, causing more than 200,000 people to flee into neighboring Turkey.