578–79 Zhukov, using a fleet of at least 4,000 trucks (IJA officers with hindsight dispute this, saying he instead used 10,000 to 20,000 motor vehicles) transporting supplies from the nearest base in Chita ( 600 kilometers away) assembled a powerful armored force of three tank brigades (the 4th, 6th and 11th), and two mechanized brigades (the 7th and 8th, which were armored-car units with attached infantry support).