This explains why US President Barack Obama was at pains to stress that, in the operation against Bin Laden's compound, US special forces were under orders to avoid civilian casualties.

BBC: Will Osama Bin Laden continue to haunt the US?

The team methodically cleared the compound, moving from room to room in an operation lasting nearly 40 minutes.

WHITEHOUSE: Press Briefing

United States forces provided limited technical support to the French forces in that operation, but took no direct part in the assault on the compound where it was believed the French citizen was being held hostage.

WHITEHOUSE: The White House