LONDON The Archbishop of Canterbury, the spiritual head of the 80-million strong Anglican Communion, said on Thursday the killing of an unarmed Osama bin Laden left a "very uncomfortable feeling."
Rowan Williams, who last week married Prince William and Catherine Middleton, said the different versions of events coming out of the White House "have not done a great deal to help here."
Bin Laden was killed by U.S. forces early Monday during a raid on his home at Abbottabad, a garrison town near Islamabad in Pakistan.
U.S. accounts of what happened have changed throughout the week, and initial characterisations of a 40-minute gun battle have given way to officials being quoted as saying only one of the five people who were killed had been armed.
Citing U.S. officials, the U.S. television network NBC said four of the five, including bin Laden himself, were unarmed and never fired a shot.
"I think that the killing of an unarmed man is always going to leave a very uncomfortable feeling because it doesn't look as if justice is seen to be done in those circumstances," Williams told reporters in response to a question at a press briefing.
"I don't know the full details any more than anyone else does. But I do believe that in such circumstances when we are faced with someone who was manifestly a 'war criminal' as you might say in terms of the atrocities inflicted, it is important that justice is seen to be observed."
Some in Europe and the Muslim world condemn the failure to arrest bin Laden as a breach of international law and have warned that this, as well as the disposal of his body at sea in a move criticised by Islamic clerics, may provoke a backlash.
The White House has cited the "fog of war" as a reason for initial misinformation on whether bin Laden -- who was shot in the head -- was armed when U.S. Navy Seals stormed into his hideout from helicopters.
Britain's embassies have been asked to review their security measures and military bases at home and abroad are on high alert for fear of reprisals.
Prime Minister David Cameron has urged the country to be more vigilant than ever.