An FIR was lodged in this connection yesterday against the victim's friends Rahul and Rahul Kumar and the latter's sister Rinki, who had helped them in the crime.
Later, Rahul Kumar and his sister were arrested from the Mehmoodabad locality in the district, police said.
According to the complaint, the woman, hailing from Sitapur, was gang-raped on August 4 when she had gone to a coaching class in Lucknow city.
The victim has been admitted to hospital, where her condition was stated to be stable, police added.
