Following instructions of the district magistrate, the Tronica City police in Loni here arrested three people on the charge of illegal sand mining from the Yamuna river, an official said on Tuesday.
DM Ajay Shankar Pandy had directed the Loni SDM to investigate the matter after receiving a complaint in this regard.
The Tronica City police was ordered to conduct a raid.
Police arrested Manoj, Mahendra and Ashok and seized three digging machines.
An inquiry had been ordered to know with whose connivance the practice was continuing, DM Pandey said.
Additional District Magistrate (Administration) Jitendra Kumar Sharma had been appointed the investigating officer, Pandey said.