Don't panic!
Air raid sirens will be tested and drills conducted across the city on September 15 local civil defense authority said.
The sirens will be sounded between 11:35am and 11:58am next Saturday. Each of the three rounds will last for three minutes and the interval between rounds will be seven minutes.
While the sirens sound, all districts will organize drills for some residents. The day before, primary and secondary schools will have evacuation drills. More than 1.7 million residents and school staff and students will take part in the drills.
Residents should be prepared and remain calm when the sirens sound.