Thailand’s telecoms regulator warned the country’s mobile operators it will revoke their licences if they are found not to have registered prepaid mobile subscribers.

The National Broadcasting and Telecommunications Commission (NBTC) made the announcement after a raft of bombings in the country’s deep south, near the border with Malaysia.

Three of the 36 mobile numbers used to organise the bombings were unregistered, while the other 33 were processed online without headshots of those registering. This raises questions about the regulator’s new SIM registration regulations, an NBTC source said.

The regulator held a meeting with all the country’s mobile operators, including MVNOs, and said it would no longer give operators warnings for unregistered SIMs and would immediately revoke their operating licences, Bangkok Post reported.

The NBTC last year set a July deadline for prepaid subscribers to register and verify personal information. The NBTC at the time it would will fine operators THB80,000 ($2,430) per day if they activate SIM cards without registering the subscriber.

Existing prepaid users had a six-month grace period to register, after which time services would be terminated.

The country has 85 million mobile connections, 83 per cent of which are prepaid, according to GSMA Intelligence.