A campaign to crackdown on people making nuisance calls as well as hoax calls to emergency services was launched yesterday.It will require all mobile phone owners in Bahrain registering with their operators before the end of the year. Telecommunication Regulatory Authority general director Alan Horne said that there were around 600,000 Batelco and Zain mobile telephone owners whose names were not registered. People who use pre-paid cards will be asked to register their telephones at Batelco and Zain offices as from September 1 and those who fail to do so will only be able to receive and make emergency calls as of January 1. They will have to turn up at one of the operators’ offices with identification.