James Bays, Al Jazeera's correspondent in Afghanistan, said: "This new report will be deeply controversial here. For many Afghans, this is a key political issue.
"The line that's coming from the International Security Assistance Force (Isaf) and the US and their new commander here, General [Stanley] McChrystal, is that the success of their mission is not about killing Taliban, it's about the number of Afghans who feel they are being protected."
Erica Gaston, from the Open Society Institute in Afghanistan, agreed and told Al Jazeera that "civilian casualty losses colour Afghan impressions of international forces and the Afghan government".
"Afghan people want protection and they want stability and if the international forces and Afghan government can't deliver that, then they will turn to other political leaders," she said.
In its grim assessment of the first half of 2009, the UNAMA said the Taliban and other anti-government fighters have become more deadly by shifting from ambush attacks to suicide bombings, roadside explosives and targeted assassinations.
It warned that more civilians would likely be killed as anti-government fighters try to battle a troop increase by the administration of Barack Obama, the US president, and seek to destabilise the country before presidential and provincial council elections on August 20.
|The UN said Taliban fighters were hiding in civilian areas to confuse security forces [AFP]
Attacks on government and international forces are "frequently undertaken regardless of the impact on civilians in terms of deaths and injuries, or destruction of civilian infrastructure," the 21-page report said.
The US and Western powers have also become more deadly, partly because anti-government fighter groups are taking cover in residential areas or luring US-led forces into unintentionally killing civilians, the report said.
The Taliban and others are "basing themselves in civilian areas so as to deliberately blur the distinction between combatants and civilians, and as part of what appears to be an active policy aimed at drawing a military response to areas where there is a high likelihood that civilians will be killed or injured".
The report said international forces have given high priority to minimising civilian casualties, but along with Afghan forces have killed 310 civilians.
Spike in violence
May was the deadliest month, with 261 civilians killed. The Taliban and other fighters were responsible for most of the deaths, but 81 were killed by government or international forces, the UN said.
The report added that two-thirds of civilian deaths caused by the Afghan government forces or its international allies came from air attacks.
Most casualties resulted from the use of close air support when troops met fighters in villages or when armed fighters took up positions in residential areas.
The report said civilians in Taliban-dominated areas can rarely refuse shelter to a fighter group, because of intimidation or traditional codes of hospitality.
The Taliban and others take advantage of these factors to use civilian homes as cover and deter attacks, or to lead the government or international forces into killing civilians, the the report added.