These operators have been instructed to pay the administrative fines by 30 June.

The letter signed by BTRC secretary Md Nurul Hafiz was recently sent to the mobile operators concerned, it said.

The BTRC fined these operators after hearing over the seizure of SIM (subscriber identity module) used in illegal VoIPs while conducting drives at various times.

The BTRC has also warned the operators to comply with some instructions.

The commission has seized 32,845 SIMs of Teletalk, 16,390 of Robi, 2,356 of Grameenphone and 753 of Banglalink, it added.