Four persons were arrested on Thursday in connection with the assault on young men and women at a homestay in Mangalore, police said.
Police had earlier arrested 15 persons in connection with the incident.
Over 12 students partying on the outskirts of the city, were targeted by suspected activists of Hindu Jagarana Vedike, who accused them of indulging in “immoral activities”, on July 28.
The attack drew widespread condemnation with government describing it as ‘inhuman’ and promising to punish those involved.