US President Barack Obama has apologised to the president of aid agency Medecins San Frontieres for a bombing that killed at least 22 people.<br />The US has said the bombing, which took place in the Afghan city of Kunduz, was a mistake and it was attempting to strike the Taliban.<br />Mr Obama has also apologised to the president of Afghanistan.<br />"If it is necessary to hold individuals accountable, that will be done," said White House spokesman Josh Earnest.
