US Edition Air raid sirens wailed across the country's northern capital and loudspeakers barked official orders as the authorities simulated a full-scale attack on the city.
The exercise caused consternation for many city residents who were unaware that a drill was planned. Some elderly inhabitants who survived the 900-day siege of Leningrad during the war collapsed and had to be treated by ambulance crews, local reporters in the city said.
Even for those too young to remember the war, the experience was an unnerving one.
"My daughter started crying when she heard the sound of the sirens," said Marina Kuznetsova, who had taken her baby for a walk in a park in the Kirov suburb of the city.
"It sounded really scary because it reminded me of the films about the War and the siege." Mrs Kuznetsova, 36, said she had been unaware of the drill, which had been announced on radio stations earlier in the day.
As over 300 sirens warned of an impending air raid, the city's committee on law, order and security interrupted radio and television broadcasts to announce that an emergency drill was under way. Instructions on how to behave in the event of a military attack or emergency were then broadcast for 14 minutes.
Critics of the Kremlin dismissed the exercise as a stunt, saying it was intended to give the impression that a Western invasion could easily happen and that it was therefore necessary to rally around the government at a time of national crisis.
Anti-western rhetoric, frequently used by Kremlin officials in recent years, has become increasingly intense since last month's war in Georgia.