Expressing solidarity with injured personnel, the association called for a comprehensive investigation into the July 20 clashes, including alleged attacks on security forces.
Additional personnel, barricades and surveillance deployed across New Delhi as police warn action against unauthorised protests during the Monsoon Session.
Haryana police initially stopped the march by offering farmers tea and biscuits and showering them with flower petals. The protesters pushed on, calling it "drama," as teargas and water jets followed.