Two more workers were arrested on Sunday night by a special investigating team (SIT) for the July 18 arson at Maruti Suzuki India Limited's (MSIL) Manesar plant.
The clash left a senior manager dead and injured more than 100 other executives.
Naresh and Virendra, who belong to Kaithal and Jind district, respectively, were produced before a local court on Monday. They were sent to 14-day judicial custody, police said.
Apart from 55 workers booked for the violence, about 600 others are on the SIT radar.
The police are on a lookout for them at various locations across the country. Around 150 workers have already been arrested, police said.