Palma's EMT public bus company announced yesterday that it is to ban the use of mobile telephones on board its buses. EMT chairman Pedro Alvarez said yesterday that the primary reason, similar to that on aircraft, is to prevent the mobiles from interfering with the new micro-chip control help systems installed on the new buses. EMT however does not intend to mount a huge advertising campaign alerting people to the new mobile phone prohibition, but will start informing the travelling public bit by bit. Braced for a backlash from the public, Alvarez said that people must understand the interference mobile telephones cause to navigational equipment. It's curious, but it is amazing the large number of travellers who use their mobiles while on the buses, he said. Alvarez also said that work on installing information signs onboard buses in different languages is progressing and soon illuminated signs will be up on all buses in Catalan and English.