The CBI has filed a supplementary chargesheet at a local court here against eight accused in the Bogtui carnage in West Bengal's Birbhum district, a senior official said on Monday.
The probe agency had on July 20 filed a chargesheet against 16 others.
Ten people had succumbed to burn injuries after their houses in Bogtui were allegedly firebombed by assailants in March, following the murder of local TMC leader Bhadu Sheikh.
The eight accused, who were not named in the FIR, were arrested on August 22.
Earlier this month, the CBI had caught the prime accused in the case.
A total of 12 people have so far been arrested by the CBI for their alleged involvement in the March 21 carnage.