All summer long, Punjabi Hindus, Muslims and Sikhs had been building up armed militias in preparation for the British withdrawal, ostensibly to defend themselves in the civil war many believed was inevitable. The Sikhs in particular feared that the new border between India and Pakistan would split their community in two; their militias had swelled from a few thousand members to nearly 20,000 by the end of July. Many of the fighters were ex-military—well-trained and battle-tested in the deserts of North Africa and jungles of Burma. Several had switched sides during World War II and fought for a Japanese-sponsored rebel force, the Indian National Army, in Southeast Asia.
Bankrolled by Hindu tycoons and Sikh maharajahs—the young and impetuous ruler of Faridkot had allegedly converted a distillery in his state into an explosives factory—they also tended to be better-armed than their rivals. Late that summer British historian Michael Edwardes—then a young soldier—stumbled across nearly 300 Sikh fighters drilling with rifles and tommy guns in a village just a few miles from Amritsar. They eagerly put on a shooting contest for him, “in which the targets were dummies of Muslim men, women and children.” The militants vowed that “there would not be a Muslim throat or a Muslim maidenhead unripped in the Punjab” when their work was done.
Link to article: http://www.caravanmagazine.in/vantage/did-sikhs-squads-participate-organised-attempt-cleanse-east-punjab-during-partition