1. Los Angeles School Police officers provide security as parents and their children gather outside of Miramonte Elementary school to protest as the investigation continues.
2. Students stand behind as a policeman and a teacher try to defend them against an intruder during an anti-violence exercise at a primary
3. Paramilitary policemen demonstrate self-defence skills to students at a school in Nanjing, Jiangsu province May 6, 2010.
4. A security guard equipped with police baton stands at the entrance of a primary school in Hefei, Anhui province May 14, 2010.
5. Students walk past a policeman guarding a school at an impoverished neighbourhood in Acapulco October 20, 2011.
6. A teacher and her students try to shut a door against an intruder during an anti-violence exercise at a primary school in Jinan.
7. Mock terrorists hold mock victims at gunpoint as part of a mass casualty incident drill, in a university in Quezon City.
8. Pupils enter a primary school in Kunming, Yunnan province May 4, 2010.
9. Students participate in an evacuation drill, in the event that they are caught in a crossfire between the army and Revolutionary Armed
10. A schoolboy and his mother pass by an armed security guard as they arrive for the first lesson at a new school No.1 in the Russian town