The girls of Talwandi Malhian village in the district were allegedly gangraped by the four boys, aged between 16 and 17 on October 7, police said.
The accused surrendered before Mehna Police Station House Officer (SHO) Inspector Gurvinder Singh, they said.
Police said the main accused and one of the victims were classmates at a school in Jagraon and were friendly.
October 7 was the birthday of the main accused and all the four accused had gone to Talwandi Malhian for celebration.
There, they saw the victims going to their school. The accused kidnapped the cousins and took them to a secluded place and repeatedly raped them, police said.