Don't call to Missed calls which starts with...?

Karnataka Telecom Circle (BSNL) has announced a important and caution message to convey to all its BSNL customers to get alert from missed calls coming from certain numbers which are starts with. +263 &  +960.

Don’t call back any missed call from unidentified/unknown International Number, especially those beginning with
+263 &  +960.
Calling to these malicious numbers may lead to charge at ISD rates.
This message is issued by Karnataka Telecom Circle in the interest of its esteemed customers.