Washington, July 8 (RHC)-- The Pentagon claims that U.S.-led coalition airstrikes against purported Daesh targets in Syria and Iraq have killed over 600 civilians since 2014. The U.S. Department of Defense said in a report on Friday that a total of 603 civilian lives had been lost between August 2014 and May 2017, with nearly half of all those deaths occurring in or near the northern Iraqi city of Mosul, the last remaining stronghold of the Takfiri terrorist group in the Arab country. The Pentagon's estimate of civilian deaths comes as independent monitors have time and again challenged such reports and revealed that the U.S.-led military campaign has significantly inflicted more civilian casualties. Airwars, a UK-based non-profit monitoring group, says at least 4,354 civilians have been killed by coalition air strikes in Iraq and Syria during the same period. The co-called Syrian Observatory for Human Rights says the 42,234 documented airstrikes in the country have resulted in a minimum estimate of some 7,000 civilians killed by the U.S.-led coalition between 2014 and 2017. In March, Amnesty International accused the coalition of "flagrant violation of international humanitarian law" as it failed to take precautions to prevent high death toll among civilians in the key Iraqi city of Mosul.