The arrests were made a day after a 24-year-old man was nabbed while allegedly trying to steal a mobile phone of a commuter in a metro train, police said.
He led the police to his other associates, including six juveniles, who were apprehended today and nine mobile phones were recovered from them, they said.
Pankaj Kumar Singh, Deputy Commissioner of Police (Metro), said the accused belong to Baha Tehsil of Agra.
They are daily wage workers and related to each other. They started committing thefts in metro trains recently to sustain their families, he added.