The siblings, aged 16 and 13, were living with their grandmother who died six months ago in Salem, Tamil Nadu. Since then they were working as servants at the house of one 59-year-old Nagasamy, they said.
Nagasamy and his relative Chandran, 40, allegedly raped them, police said, adding that the girls escaped from their clutches and were found by a service organisation wandering at the bus stand in Salem
The matter came to light after the organisation's volunteers questioned them.
A case under IPC section 376 (rape) and Women's Harassment Act was registered and the two men were arrested today, police said.
The girls were handed over to the 'Childline' service organisation.
On December 22, a 13-year-old girl was found murdered at Syedunganallur, about 30 km from Tuticorin. Injury marks on the body of the Std VII student gave rise to suspicion of rape and a 35-year-old man has been arrested in connection with the incident.