sentences:  Indeed, the Chinese warlords used the incident as a pretext to further their own political aims.While Feng Yuxiang threatened to attack British interests militarily and demanded a national apology, Zhang Zuolin, who effectively controlled Shanghai's Chinese outskirts, had his police and soldiers arrest protesters and Communists and assist the Settlement forces.Two investigations into the events of May 30 were ordered, one by Chinese authorities and one by international appointees, Justice Finley Johnson (presiding), Judge of the Court of First Instance in the Philippines (representing America), Sir Henry Gollan, Chief Justice of Hong Kong (representing Britain) and Justice Kisaburo Suga of the Hiroshima Court of Appeal (representing Japan).