By Jack Kimball
KABUL, May 11 (Reuters) - After five years of rising deaths, civilian casualties in Afghanistan dropped 20 percent in the first four months of the year, the United Nations said, a rare piece of good news as foreign combat forces prepare to pull out by the end of 2014.
The killing of civilians has soured the feelings of many ordinary Afghans towards foreign forces and has been a constant strain on ties between the Afghan government and its Western backers in the increasingly unpopular war.
"There are several elements behind this ... there was perhaps less fighting in the first four months," Jan Kubis, the U.N. special envoy to Afghanistan, said late on Thursday.
"Secondly, indeed, the pro-government forces and notably the international military are taking efforts to reduce civilian casualties. Unfortunately there have been, but they take measures," the former Slovakian foreign minister told Reuters.
Kubis declined to give the number of people killed and injured in the January-April period but said the figure would be published before a meeting in Chicago later this month when NATO leaders discuss funding for the Afghan security forces.
The 20 percent decline was from the same period a year earlier.
The harshest winter in 30 years may also have had something to do with the drop in civilian casualties, which have steadily risen over the years, mostly driven by increased attacks by insurgent groups, rights groups say.
In Afghanistan, fighting usually falls off during the winter months and picks up again once heavy snows melt - insurgents are already mounting a spring campaign of suicide attacks, including high-profile assaults in Kabul.
In 2011, more than 3,000 civilians were killed and another 4,500 injured by roadside bombs, suicide attacks and other bloodshed in the country, a five percent rise from 2010.
"The bulk, the overwhelming majority, of civilian casualties are caused by the actions and activities of the anti-government forces, including such terrible instruments like, increasingly, suicide bombers," said Kubis, who is fluent in five languages.
Despite a Taliban pledge at the start of the summer fighting season that its top priority would be protecting civilian lives, a powerful roadside bomb killed seven Afghans including five children in Helmand province on Thursday.
Following a series of recent civilian casualties blamed on NATO, President Hamid Karzai said a strategic partnership agreement signed with the United States earlier this month was at risk of becoming "meaningless" if Afghans did not feel safe.
Ties between Kabul and Washington have already been strained over a string of incidents involving U.S. forces this year, including the killing of Afghan villagers for which a U.S. soldier was charged and the inadvertent burning of copies of the Koran.
Kubis said he saw a "very clear desire" by international forces to prevent civilian casualties.
"Definitely, I see a much stronger effort to address this problem on the side the pro-government forces and on the side of ISAF (the International Security Assistance Force)," he said. (Reporting by Jack Kimball)