 As of 30 April, the Soviet forces were joined by the Polish 1st Tadeusz Kościuszko Infantry Division after a request from the Soviet command for infantry reinforcements.Originally, one infantry regiment was to support the 1st Mechanised Corps, and two, the 12th Guards Tank Corps; contrary to the original plan, two regiments (1st and 2nd) ended up supporting the 1st Corps, and only one (3rd) the 12th Corps.The 3rd Polish Infantry Regiment was operating with the 66th Guards Tank Brigade of the 12th Guards Tank Corps.