An explosion shredded a bus carrying Israeli tourists outside an airport in Bulgaria. At least four people were killed and dozens injured.<br/> <br />Police say several others buses were also damaged.<br/> <br />Israeli Defense Minister Ehud Barak blamed Tehran for the blast and said Israel would respond.<br/> <br />The explosion comes on the 18th anniversary of a 1994 bomb attack on the headquarters of Argentina's main Jewish organization -- which killed 85 people.<br/> <br />Deborah Gembara, Reuters.
