"Over 100 hours & Modiji hasn't uttered a word on Dalit killings in Haryana - yet him invoking Gandhiji's ideals is nothing but preposterous," Kumar said in a tweet message.
He referred to the Faridabad incident during his election rallies in the day at Lalganj in Vaishali and other places.
At Lalganj, Kumar said "BJP leaders talk of jungle raj in Bihar. Is the Haryana incident an example of Mangal raj?"
At the same election meeting in Vaishali district, Kumar also raised the controversial dog remark against Dalits by union minister V K Singh to highlight the "insenstivity" of NDA ministers.
In such a condition, the Faridabad incident has spelt trouble for NDA as it has given the grand secular alliance an opportunity to attack it.