A suicide bomber killed at least 57 people at a volleyball game in Afghanistan’s eastern Paktika province last Sunday.
Most of the dead were young players and spectators. The next day a bomb attack on a convoy killed two Nato officers.
The country is in the grip of instability, with Taliban forces showing their strength.
US president Barack Obama announced that the 10,000 US troops that remained after the final pull-out date of 31 December could continue to play a combat role.