At least one person was killed and several were wounded following the blast which occurred early on Saturday morning in the Egyptian capital - images from Egyptian media show the damage caused.
Italy's foreign minister, Paolo Gentiloni, said on Twitter that there were no Italian victims and that his country 'would not be intimidated' by the attack.
The six month exhibition focuses on food technology and runs from May 1st to October 31st, with organisers hoping to attract 20 million visitors over that time period.
Previous cities to host universal exhibitions include Aichi, Hannover, Zaragoza, Yeosu and Shanghai.
Nicola Borri, an assistant professor of economics at LUISS university in Rome told CNBC that the total cost of the expo to the Italian state could be as much as €12.5 billion.
There have been protests in Milan about the perceived waste of public money on the expo in recent days.