futility of static defence, Blackburn adopted mobility, counter-flanking movements and defence-in-depth as his maxims for Blackforce. Blackforce was able to re-equip itself to a significant extent from the Tanjung Priok wharves, where it obtained hundreds of Bren machine guns and Thompson submachine guns, grenades, ammunition, and vehicles, from stocks originally intended to re-supply Singapore. Heavy weapons remained in short supply, although a few mortars and light armoured vehicles were available. Blackburn's Dutch commanders directed him to disperse his force to protect five airfields from paratroop drops, orders which Blackburn only grudgingly obeyed, as he was concerned about splitting Blackforce. On 20 February, it divided itself between the various airfields, where its members established defensive positions. Blackburn set up his headquarters in Batavia. On 23 February, Blackburn went to Schilling and asked that he be permitted to concentrate his force for training, but this was refused. The following day, Blackburn was summoned to General Sir Archibald Wavell's American-British-Dutch-Australian Command headquarters in Bandung where he met with Wavell. He was directed to use his force in offensive operations against the Japanese. On 25 February, Sitwell and Schilling permitted Blackforce to be concentrated for this purpose, and Sitwell attached a United States artillery unit, a British signals section, and a squadron of 16 obsolescent light tanks to Blackburn's command. By 27 February, Blackburn had established his headquarters in Buitenzorg, on the road between Batavia and Bandung. Blackforce was to be kept as a mobile reserve to strike the Japanese once they landed, with the Dutch conducting delaying actions. On the following night, the Japanese landed a division in the Merak area on the northwestern tip of Java, and a regiment east of Batavia at Eretanwetan. Both landings were unopposed, and the regimental one was guided in by fifth-column elements among the population. Another division and additional regiment landed further east along the Java coast. The Japanese forces that landed on Java numbered 25,000. Arrayed against them was a Dutch force of the same strength with a ratio of one Dutch to 40 locally recruited troops. Many of the local troops viewed the Japanese as liberators from Dutch colonialism rather than an enemy to be resisted. The Japanese advance from Merak progressed swiftly, covering by noon on 1 March, with the Dutch putting up little resistance. The Japanese force quickly captured Serang then split into two, with one column pushing east along the north