Security agent, 保安員/ 國安

Security agents walk alongside Chinese President Xi Jinping's (silhouetted, 2nd R in window) car as he arrives to attend the upcoming Nuclear Security Summit meetings in Washington, on the tarmac at Joint Base Andrews, Maryland March 30, 2016. (Photo by Jonathan Ernst/Reuters)
The Day in Photos – April 1, 2016
http://avax.news/fact/The_Day_in_Photos_April_1_2016.html

Security agency - Wikipedia, the free encyclopedia

國家安全機關也稱國家安全部門，簡稱國安機關、國安部門、國安

Security agent, Security officer, Security personnel, Security guard. 保安員, 安全官, 安全人員, 保全
http://okok1111111111.blogspot.tw/2016/03/security-agent-security-officer.html