Damascus, Jan 12 : A war monitor has revealed that 600 people were killed between June and October 2017 during the US-led airstrikes targeting positions of the Islamic State (IS) group in Syria's northern province of Raqqa. According to a report published on the website of the Syrian Observatory for Human Rights on Tuesday, the US-led bombings in Raqqa, the former de facto capital of the IS, killed 600 people from 140 families over the course of the four months, Xinhua news agency reported. Their bodies were found when mass graves were uncovered after the IS was defeated in Raqqa, according to the report. The overall number of people killed by US-led airstrikes is much higher, as evidenced by the 28 mass graves housing more than 6,000 bodies, said the Britain-based observatory, adding the majority of the victims were killed during US-led airstrikes targeting IS positions in Raqqa between 2014 and 2018, while the rest were killed by the IS following its capture of Raqqa in 2014. /IANS