Sunday's bombing of a tourist bus near Egypt's Great Pyramids of Giza bore striking resemblance to an attack that targeted a similar vehicle five months ago, something that showcases the security challenges in one of the most visited areas in the Egyptian capital.
Roadside bombs, possibly remotely detonated, were used in both attacks, which took place in generally the same area around the pyramids and the historical area of Saqarra and the under-construction Grand Egyptian Museum – all of which are on the western outskirts of Cairo.
Sunday's attack injured 16 people, including 12 South African tourists. The December blast killed three Vietnamese tourists, their Egyptian guide and wounded at least 10 others.
Similarly, a deadly May 2017 attack by Islamist militants on buses carrying Christian pilgrims to a remote desert monastery west of Cairo was repeated 18 months later on the same road, raising questions about whether the tighter security measures introduced after the initial attack became lax as time went by, thus allowing the militants to strike again.
The two attacks left a total of 37 people dead.
The Cairo area where the two bus attacks took place is normally crawling with police. There are also checkpoints along some roads. The area has become notorious for attacks by militants, who have on several occasions gunned down policemen on the street before escaping into nearby villages in rural Giza.
Following the attack in December, authorities resurrected regulations that oblige tour operators to provide the police with a detailed itinerary in advance for their tourist buses as well as the vehicle's details and the names of the guides and drivers.
But it is easy to see how the attacks on Sunday and in December were possible. Much of the area where they took place is farmland, heavily treed or dotted with the often empty holiday homes of wealthy Cairenes thus allowing perpetrators to stealthily plant bombs, find hiding places or ambush police.
With the impossibility of deploying policemen around the clock on every street corner, Egypt has been making growing use of security cameras to monitor roads and tourist sites, but not enough. However, Sunday's attack is likely to prompt wider use of the cameras to stop anyone from planting roadside bombs.
There was no immediate claim of responsibility for Sunday's attack, which bore all the hallmarks of Islamist militants who have been fighting security forces for years. The epicentre of the insurgency is in the Sinai Peninsula, but attacks also take place on the mainland. Egypt has over the past 12 months managed to prevent high-profile attacks by the militants in Sinai, but smaller groups continue to wage attacks in Cairo.
While Sunday's attack near the Pyramids caused no fatalities, it is likely to affect Egypt's vital tourism sector, which has been making a marked recovery after years of turmoil following a 2011 uprising.
It is too early to speculate on the extent of the damage, but Egyptian officials would be hoping that some of it could be offset by the resilience of Egypt's reputation as one of the best tourist destinations of 2019 as well as the publicity blitz the country launched recently to boost the number of visitors.