The number of Afghan civilians killed in US and Nato air strikes dropped by nearly half last year to 126, the UN said today.
The report came a day after Afghan president Hamid Karzai banned government forces from requesting foreign air support during operations in residential areas.
The overall civilian death toll last year also declined 12 per cent to 2,754, from 3,131 the previous year, according to an annual report by the United Nations Mission to Afghanistan which tracks statistics in the 11-year-old war.
While it was the first reduction in casualties in six years, the UN expressed concern about a spike in targeted killings and human rights abuses by armed groups, a worrisome trend as foreign powers prepare to withdraw combat troops by the end of 2014.
It also said the number of Afghan women and girls killed and injured in the conflict increased by 20 per cent in 2012.
The report was released as anger is high over an air strike last week in north-eastern Kunar province which killed five children, four women and one man along with four insurgents.
Mr Karzai, angry that the strike was requested by his national intelligence service, ordered government troops to stop asking for foreign air support in residential areas.
The Taliban and other insurgents increasingly targeted civilians throughout the country and were responsible for 81 per cent of the civilian casualties last year, the UN said. The report said so-called anti-government elements killed 2,179 civilians and wounded 3,952, a 9 per cent increase from 2011.
By contrast, the number blamed on US and allied forces decreased by 46 per cent, with 316 killed and 271 wounded in 2012.
The senior UN envoy in Afghanistan, Jan Kubis, welcomed the decline in casualties but said "the human cost of the conflict remains unacceptable".
The Afghan interior ministry also said the decrease was a positive sign and pledged to do everything possible to stop the insurgents from attacking civilians.
"They're still using suicide bombers, they still use IEDs (improvised explosive devices) in the very populated areas and they still use civilians as a shield in the villages," ministry spokesman Sediq Sediqi said.
“The important thing is that civilian (casualties) should be decreased to zero.”
The report attributed the overall drop in civilian casualties to a decline in suicide attacks, reduced numbers of air strikes and other measures taken by the US-led coalition and the Afghan government.
It also cited "an unseasonably harsh winter which impeded insurgent movements and effects of earlier military operations against anti-government elements" and said the number of civilian casualties actually rose in the second half of the year.
Despite the decline, air strikes remained the cause of most civilian deaths and injuries by the international military forces and 51 of those killed were children, the report said.
The death of civilians during military operations, particularly in air strikes, has been among a major source of acrimony between Mr Karzai's government and foreign forces.
The US-led military coalition said last June that it would only use air strikes as a self-defence weapon of last resort for troops and would avoid hitting structures that could house civilians. That announcement followed a bombardment that killed 18 civilians celebrating a wedding in eastern Logar province, which drew an apology from the American commander.