President Abdel Fattah al-Sisi told visiting Vietnamese leaders in May that he was keen to revive Vietnamese tourism in his country, according to Egypt Today.
An interior ministry statement said ten other tourists from Vietnam as well as the Egyptian bus driver were wounded when the homemade device exploded in the early evening.
There was no immediate claim of responsibility for the blast.
TRT World spoke with Cairo-based journalist Maged Atef for more details.
Armed security personnel quickly deployed to the site and cordoned off the area for inspection.More news: Jurgen Klopp: Liverpool Need 105 Points To Win Premier League
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Prime Minister Mostafa Madbouly was reported to be following the attack's updates along with the interior minister, Giza Governor and other security bodies.
Madbouli said that the Egyptian tour guide had died in hospital from his wounds.
Those events and the bombing of a Russian airliner shortly after it took off from Sharm el-Sheikh in 2015 caused tourist numbers to plunge.
During the past two years, militant attacks against Christians in Egypt - usually targeting churches or buses carrying pilgrims to remote desert monasteries - have killed more than a hundred people.
Egypt has battled Islamic militants for years in the Sinai Peninsula in an insurgency that has occasionally spilled over to the mainland, hitting minority Christians or tourists.