The Gurgaon Additional District and Sessions Court on Friday convicted 31 Maruti Suzuki workers in connection with a riot in 2012 at India’s largest automobile manufacturer’s factory in Manesar, Haryana. After four years of trial, Additional District and Sessions Judge RP Goyal acquitted 117 workers, ANI reported. The quantum of punishment will be announced on March 17.

The case dates back to July 18, 2012, when senior manager Awanish Kumar Dev died and several others were injured in a fire that broke out at the plant during a clash between workers and the management. The workers were arrested and charged with murder, rioting and unlawful assembly.

Tension had been brewing in the factory for a while before the incident. In 2011-2012, more than 4,000 workers went on strike three times to demand better work conditions and the right to form an independent trade union. Even after the union was formed, relations between the workers and management continued to be strained. Of those arrested, 113 got bail in 2015. Eleven workers who were members of the Maruti Suzuki Workers’ Union were denied bail and are still in Bhondsi prison.

Maruti Suzuki Workers’ Union members on Thursday boycotted food at the factory canteen in solidarity with the accused, reported Hindustan Times. “The workers across the industrial belt are united and in one voice want the government to drop charges against those who have been framed wrongly,” General Secretary Kuldeep Janghu told the daily.