The trader Pradeep Agrawal's son Abhishek has been missing since yesterday after he visited his friend Satyam Kumar's house, the sources said.
Following complaint by the father, the boys' two friends, Shashi Kumar and Sharad Kumar, were detained for questioning.
Nine mobile phones and 16 SIM cards have been recovered from the two detainees, the sources said, adding Satyam and his father Sudhanshu Kumar were absconding, the sources said.
An investigation was going on in the matter, they said.