NEW DELHI: Hundreds of army and paramilitary soldiers on Saturday tried to quell protests by angry mobs demanding government benefits in a northern Indian state, with at least four people killed in clashes between security forces and protesters, officials said.

The violence raged for a second straight day, as protesters burned a railroad station and attacked shops and vehicles in several towns in Haryana state, said police officer Y.P. Singhal.

Protesters also blocked a highway linking New Delhi to key northern cities, he said, adding that authorities ordered police to fire without warning at those instigating violence.

Authorities used helicopters to bring in army soldiers to the worst-hit districts of Rohtak, Bhiwani and Jhajjar, where curfews were in place, Singhal said.

Four people were killed in clashes between security forces and protesters, said Federal Rural Development Minister Chaudhary Birender Singh. Police said 78 other people have been injured since Friday.

The protesters were driven by members of the Jat agricultural community, who are demanding benefits both at the federal and state levels, including guaranteed government jobs or university spots. Talks Friday between community leaders and state government representatives failed to lead to an agreement.

India's constitution includes a system of affirmative action for people in the lowest castes to help them overcome discrimination. The government has expanded the number of groups, including the Jat, qualifying for quotas.