At the end of July, seven union officials were sentenced to 12 months' jail and one to six months, with fines being imposed on other officials and three unions. Chifley told the Labor caucus, "The Reds must be taught a lesson", while Arthur Calwell threatened to put communists and their sympathisers into concentration camps.[https://www.greenleft.org.au/node/19445] On 1 August 1949, 2500 soldiers commenced coal mining at the open cut mines of Minmi (near Newcastle), Muswellbrook and Ben Bullen, with seven more fields operated later.