An officer from Cambodia's anti-terrorism unit stands guard as fire fighters take part in an emergency exercise at a military air base in Phnom Penh February 2, 2010. The Cambodian National Committee for Management Disaster and Societe Concessionaire des Aeroports (SCA) organized the fourth full scale airport emergency exercise to improve the airport community's ability to face a major crisis. REUTERS/Chor Sokunthea (CAMBODIA - Tags: SOCIETY)