In 1941, 16 groups of national volunteers (more than 160,000 people), twenty-five battalions (18,500 people) and four engineering regiments were created among the Muscovites. That November, the German Army was stopped at the edge of the city and then driven off in the Battle of Moscow. Many factories were moved away, and much of the government was too, and from 20 October the city was declared to be under siege. Its people who stayed built and used anti-tank defences, and the city was bombed from the air. Joseph Stalin (the leader of Russia) did not leave the city, so the general staff remained in the city as well. Even with a siege going on, the construction of the Moscow Metro system continued through the war, and by the end of the war a few new metro lines were open.