AT LEAST 12 presidential guards were killed after a suicide bomber believed to belong to the Islamic State detonated a bomb on board a crowded bus on Tuesday evening just yards from the country's Interior Ministry in the Tunisian capital Tunis. The terrorists are believed to have meant to target President Beji Caid Essebsi, but instead almost killed Tunisia's ex-president Moncef Marzouki. This is the third major terrorist attack in Tunisia this year following the drug-crazed fanatic Seifeddine Rezgui who opened fire on a tourist beach at Sousse, killing 38 people including 30 Britons in the Mediterranean resort town of Sousse in the south of the country, and earlier in March when Islamic State gunmen stormed the Bardo Museum in Tunis slaughtering 22 tourists, mainly Europeans. Tunisia is facing a terrorist onslaught, but terrorism has emerged as a global phenomenon.