A senior United Nations human rights official has accused Afghan and international forces of a lack of transparency and accountability over the deaths of civilians in armed raids around the country.

The UN special envoy on extrajudicial killings, Australia's Philip Alston, was speaking in Kabul after a 12-day tour of Afghanistan.

He says most of the deaths were caused by air strikes.

"In terms of the international military forces, it has been reported that as many as 200 civilians have been killed in the first four months of this year, often in joint operations with Afghan security forces," he said.

Mr Alston also says another 300 civilians were killed by the Taliban militia and associated groups so far this year - three quarters of them during suicide attacks.

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