ROUGH CUT - NO REPORTER NARRATIONbr br Security in the Afghan capital Kabul was tight on Sunday (December 28) ahead of a ceremony set to mark the end of NATO combat missions in the country.br br The ceremony will formally draw to a close 13 years of combat operations in the conflict in the country, which have left the country in the grip of worsening insurgent violence.br br Police armed with automatic weapons were seen searching vehicles and individuals on the streets, a day after Afghanistan's NATO-led foreign force mistakenly killed three civilians in an air strike, Afghan officials said on Saturday (December 27).br br The mistaken killing of civilians in air strikes has been a source of anger throughout the force's mission, frequently straining ties between the NATO force and the government.