Over 30 people, including policemen, were injured after the Haryana Police resorted to lathicharge on hundreds of protesting workers of Liberty Footwear who had blocked National Highway No 1 near Gharaunda on Monday afternoon.
Police officials said that they had to resort to lathicharge after the workers pelted stones at them and refused to lift the blockade.
About six policemen sustained injuries in the stone pelting, they said.
Many of the workers, including women, were detained to clear the highway that had remained blocked for over three hours, leading to nearly 10-kilometre-long queues of stranded vehicles on either side of the industrial town of Gharaunda.
The highway, also known as the Grand Trunk Road that connects Delhi with many important cities in north India, was reopened for traffic later in the day.
The workers' union has been on strike for the last four months. Police said that the workers had beaten up two company officials on Monday following mounting tension between both sides over the weekend.
A large contingent of policemen from Karnal and Panipat was rushed to the spot after the workers blocked the highway. As the police officials asked them to lift the blockade, the workers started pelting stones on the force.
The police action brought back memories of the cane-wielding Haryana police mercilessly beating up striking Honda Company workers in Gurgaon on July 25 last year.