The UN's top official in Afghanistan says he is taking "very seriously" the US-led air strike in the west of the country earlier this week which left dozens of civilians dead.

Kai Eide, UN Special Representative in Afghanistan, said, "We take that kind of incident very seriously. I have spoken several times with Commander and General McKiernan. I think the facts on the ground are still unclear. There is investigations going on. We certainly also would like to send our team there as soon as possible to try to clarify what has actually happened. But there is no doubt it seems to have been a serious incident, circumstances are unclear."

(CCTV May 7, 2009)