By Magdi Abdelhadi
BBC Arab affairs analyst
The recent explosions in Algiers and the foiled suicide attacks in Morocco have raised fears that North Africa may be facing a new surge in radical Islamist violence.
The bombs in Algiers killed at least 33 people
At least 33 people were killed in the attacks in the Algerian capital on Wednesday, and many more were injured, some seriously.
Algiers has not seen violence on this scale since the days of the bitter conflict between Islamist rebels and the Algerian army back in the 1990s.
A day earlier in neighbouring Morocco, four men fitted with suicide belts and one policeman were killed. The Moroccan authorities said the men were planning attacks on strategic and foreign targets.
In Tunisia, where an iron-fist approach to security has quashed Islamist opposition for years, 12 militants were killed in January after a fierce gun battle with security forces.
The Tunisian authorities said they were militants who had crossed the border from Algeria.
All this paints a very disturbing picture for the governments of the three North African countries as well as security officials in the wider region.
The question is, how much of this resurgence is strictly home-grown and how much is inspired - or even financed - by Osama Bin Laden?
The truth may never be found out. The lines between local Islamism and al-Qaeda's global jihad have often overlapped.
Morocco said militants were planning attacks on strategic targets
The Moroccan authorities have played down the possibility of a link between the latest incidents in Casablanca and the blasts in Algiers.
But there is broad agreement among observers that this is the work of al-Qaeda.
The group which has claimed responsibility for the attacks in Algiers is a well-known radical Algerian organisation that has rejected the amnesty offered by President Boutafliqa two years ago and vowed to continue to fight a regime it believes is corrupt and ungodly.
It had recently sworn allegiance to al-Qaeda and changed its name from the Salafist Group for Preaching and Combat into al-Qaeda in the Maghreb.
Arab fighter volunteers
There is also the use of al-Qaeda's most feared weapon: the suicide bomber and the simultaneity of the attacks - a well-known tactic employed by al-Qaeda and widely used in Iraq.
The possibility of a connection with Iraq would be extremely worrying for the North African governments.
A number of Algerians, Tunisians and Moroccans are known to have joined the ranks of Arab fighters in Iraq and some of them may have started to return home.
The attacks are a serious blow for the Algerian authorities which, unlike their Moroccan counterparts, have failed to anticipate and thwart them.
Morocco was hit by suicide bombs in 2003
They will undoubtedly revive fears of a return to the violence of the 1990s when an estimated 100,000 Algerians were killed in fighting between Islamist militants and the Algerian army.
The spectre of a resurgent al-Qaeda operating in North Africa, close to Europe's southern borders, will set the alarm bells ringing in European capitals.
It may also have a devastating impact on the prospect of more open and democratic societies in North Africa. Like other Arab states, the authorities there have used the threat of terror in the past to curb civil and political freedoms.