By Gordon Corera
BBC News security correspondent
The third attack on the Sinai peninsula in 18 months, at Dahab, will be a major concern for the Egyptian authorities.
There are concerns over Egypt's ability to provide security
They have said they received no warning ahead of the latest bombings, and that it is too early to know who was behind them.
But while the explosives used in the Dahab attack may be more primitive, there are some similarities between the three attacks in terms of geography and methodology.
This will raise questions about whether there is some kind of connection and whether a network remains active and able to carry out further attacks.
The first attack in Taba, in October, 2004, killed 34 and at the time, was seen primarily as targeting Israeli tourists.
But with the second attack in July 2005 on Sharm al-Sheikh, which killed 64, it become clear that the problem was not isolated, and that it was aimed more broadly at Westerners as well as Israelis.
It also looked as if the problems came from a local group.
There were huge security sweeps following both the earlier attacks, with thousands of individuals picked up.
The government pointed the finger at Bedouin groups who live in the interior of the Sinai region for providing support to the militants who carried out the bombings.
There are some within that community who are resentful and angry at both Western tourists who have come into the region, as well as the Egyptian state - not least for the heavy-handed arrests following each raid.
There had been reports in the Egyptian press that some of those believed to have been involved in the Sharm al-Sheikh attacks had eluded security forces and remained at large, and their involvement in the latest bombing is clearly possible.
Security had been increased in Sinai following earlier attacks, with more checkpoints put in place at entrance and exit points and a fence constructed.
But the difficult terrain makes it easy for tribes who know the area to move both people and explosives, probably along the same routes used to smuggle drugs across the region.
Since these new security measures clearly failed, there will now be questions over whether enough can be done to prevent more attacks.
After the previous bombings, there was not as much of a dip in tourist numbers as some expected, and nothing like the problems seen after the brutal killing of more than 60 people in 1997 in an attack in Luxor.
Zawahiri is regarded as Bin Laden's right-hand man
But the concern will be that as the attacks continue, they will begin to have a major impact on the tourist industry which is so important for the local economy.
There were also be concern that this attack may undermine confidence in the ability of the Egyptian state to provide security.
The attack did come shortly after the release of a new audiotape from Osama Bin Laden.
However, the narrow interval between the two events makes it unlikely that a group could have put together an attack from scratch immediately after the message.
If anything, an earlier tape in March from Ayman al-Zawahiri is more likely to have had an impact - Zawahiri is Egyptian, as have been many of al-Qaeda's key figures.
The most likely scenario, though, is that the group who carried out the Dahab bombings were inspired by al-Qaeda and its ideology, but not necessarily directed by its leadership.