Security forces stand near a tourist bus after a roadside bomb in an area near the Giza Pyramids in Cairo, Egypt, Friday, Dec. 28, 2018. Egypt's Interior Ministry said in a statement that two Vietnamese tourists were killed and others wounded in the incident.[Photo: AP/Nariman El-Mofty]

The damaged tourist bus after a roadside bomb in an area near the Giza Pyramids in Cairo, Egypt, Friday, Dec. 28, 2018. Egypt's Interior Ministry said in a statement that two Vietnamese tourists were killed and others wounded, in the incident.[Photo: AP/Nariman El-Mofty]

Security forces stand near a tourist bus after a roadside bomb in an area near the Giza Pyramids in Cairo, Egypt, Friday, Dec. 28, 2018. Egypt's Interior Ministry said in a statement that two Vietnamese tourists were killed and others wounded, in the incident.[Photo: AP/Nariman El-Mofty]