In the north the defensive line against the Finns, the Karelian Fortified Region, had been maintained in Leningrad's northern suburbs since the 1930s, and was now returned to service.
En tredje linje mod finnerne, den Karelske Befæstede Region, var blevet opbygget i de nordlige forstæder af Leningrad i 1930'erne og blev nu taget i brug igen.