The acceptance of the Nobel Peace Prize by Barack Obama, the US president, has sparked constroversy.

Obama received the prize dedicated to peace in Oslo, pledging to strive for a better world and pursue building a "just and lasting peace".

But critics have attacked the decision to award the prize to Obama, pointing out he is actively leading his nation in the wars in Afghanistan and Iraq and last week ordered 30,000 more troops to join the Afghan conflict.

Tim Friend reports.