An Afghan police officer shot dead at least 11 of his colleagues in south-west Afghanistan on Sunday. The attack follows two other incidents where Afghan security forces turned their weapons on NATO forces. The latest incident occurred in the Delaram, in south-western province of Nimroz. Local officials have described the shooter as a “Taliban infiltrator”. It has also been a violent 48 hours for foreign troops in the troubled Helmand province. On Friday, three US Marines were shot dead by an Afghan police commander and his men after they accepted a dinner invitation.