Foreign and government forces are responsible for 717 deaths, while anti-government elements (including Taliban) caused 531 deaths, the United Nations found.
In total, the UN documented 3,812 civilian casualties (1,366 deaths and 2,446 injured) in the first half of the year.
The UN “continues to regard the level of harm done to civilians as shocking and unacceptable,” the global agency said.
Parties to the conflict may give differing explanations for recent trends, each designed to justify their own military tactics,” said Richard Bennett, Human Rights Chief of the UN Assistance Mission in Afghanistan.
“The fact remains that only a determined effort to avoid civilian harm, not just by abiding by international humanitarian law but also by reducing the intensity of the fighting, will decrease the suffering of civilian Afghans,” Bennet continued.
The latest casualty figures were released as talks between the Taliban and US officials to end the 18-year Afghan war entered an important stage.
The United States is trying to negotiate a deal under which foreign forces would pull out in return for security guarantees by the Taliban, including a pledge that the country will not become a safe haven for terror groups.
Colonel Sonny Leggett, a spokesman for US forces in Afghanistan, rejected the methods and findings used by the UN, saying the collection of evidence by US forces was “more thorough, evidentiary and accurate”.
Leggett, however, did not give any US military figures for civilian casualties but said US forces worked closely with Afghan security forces to prevent them.