 Complete the following phrase:  As part of this process, Virsaitis joined the Soviet Baltic Fleet on 19 August 1940 as a minesweeper, and was renamed T-297. Germany invaded the Soviet Union on 22 June 1941. T-297, which was redesignated as an escort vessel on 25 July 1941 returning to the name Virsaitis, was used to defend naval bases and communication routes. From 31 October 1941, the Baltic Fleet carried out a series of convoy operations to evacuate the garrison of the Hanko Peninsula, which the Finns had been forced to lease to the Soviets for use as a naval base following the Winter War between Finland and the Soviet Union, but was now 