The girl has eloped with a boy and they were planning to go to Lunglei last night, police said.
"The boy who eloped with the girl was accompanied by seven friends. The girl was allegedly raped when the boy went back to the village to pick up his wallet which he left behind while leaving in a hurry," police said.
Three of the rapists are adults while the rest four are minors. Three of minors are 14 years of age and one of them 16 year-old, they said.
All the seven accused have been arrested, police added.