The United Nations on Tuesday called for an immediate reduction of violence in Afghanistan, warning that civilian deaths by both the Taliban and Afghan security forces are on the increase.
The UN mission also expressed concern about stepped-up attacks and brutality of the Islamic State group.
A horrific attack last week at a maternity hospital in the Afghan capital has not been claimed by any group, but the United States said it bears all the hallmarks of Afghanistan's IS affiliate targeting the country's minority Shiites in a neighbourhood of Kabul that IS militants have repeatedly attacked in the past.
The Taliban denied involvement in the maternity hospital attack, which killed 24 people, including two infants and several new mothers.
The UN report blamed the Taliban for killing 208 civilians last month and also said that operations by Afghan forces in April had killed 172 civilians.
Civilians are often caught in the crossfire of the fighting and Afghan forces say they are targeting the insurgents, not civilians, in anti-militant operations.
Parties have committed to finding a peaceful solution and should protect the lives of all Afghans and not jeopardize people's hope for an end to the war, said Deborah Lyons, the UN chief's special representative to Afghanistan.
She added that intra-Afghan peace negotiations need to start as soon as possible."