Three Vietnamese tourists and their Egyptian tour guide were killed in a bomb attack near the Giza Pyramids on Friday, Reuters reports. At least 10 other people were also injured, including nine Vietnamese nationals and an Egyptian bus driver. Prime Minister Moustafa Madbouly told reporters the bus driver deviated from a secure, pre-planned route. The prosecutor general has ordered an investigation into the incident, a first of its kind in over a year. No group has claimed responsibility for the attack, but the Interior Ministry said security forces killed 40 suspected terrorists in three separate operations across the country the next day. The ministry did not clarify whether the operations and those killed were directly tied to Friday’s attack.

The “immediate fallout” from the attack on the nation’s still-recovering tourism sector will likely be limited, the National says, despite the timing of the incident being less than ideal. Tourists continued to visit the pyramids, seemingly unshaken by the attack, say AFP and EuroNews. Thomas Cook suspended Hurghada-Cairo trips in response to the attack and said it will continue to monitor the situation closely, according to Reuters. Bloomberg and the Associated Press also had the story.

Egypt is pushing to break the 2010 high water mark for tourism, with reports in late November suggesting this winter was shaping up to be a particularly solid season.