Authority announced a 6-month trial of enhanced security screening that would take place at selected stations. The trial began shortly after on 12 November, with up to six stations randomly selected to conduct the checks for a period of time. The stations are – Ang Mo Kio and Bedok (November 2018), Promenade (December 2018), Chinatown (February 2019), Tampines and Clementi (March 2019). Checks are done one person at a time to reduce delays, and the data obtained from the trial would be used to improve the screening process. Announcements & notices Recorded audio announcements such as the above played in stations & trains respectively, notices on plasma display screens on station platforms and in train carriages, as well as posters and notices in stations remind commuters to report instances of unattended packages and other suspicious activities to the authorities. Exercise Northstar V On 8 January 2006, a major civil exercise, codenamed Exercise Northstar V and simulating bombing and chemical attacks at Dhoby Ghaut, Toa Payoh, Raffles Place and Marina Bay MRT stations was conducted. Thirteen affected stations were closed during the three-hour duration of the exercise, affecting about 3,400 commuters. Exercise Station Guard Since 2018, the Land Transport Authority launched Exercise Station Guard, an emergency preparedness ground deployment exercise intended to test the adequacy of existing security measures and maintain vigilance for quicker and effective responses. The first test was held at Newton MRT station, followed by Holland Village MRT station. Notes Counterterrorism in Singapore Mass Rapid Transit (Singapore)