A total of 3,000 troops are searching the wooded and mountainous region of Kabylia where Gourdel was captured and apparently held by the recently formed Jund al-Khilafa (Soldiers of the Caliphate).
The opposition Rally for Culture and Democracy (RCD), whose support comes largely from the region’s majority Berber population, had called a demonstration in Kabylia’s main town, Tizi Ouzou, to call for Gourdel’s liberation.
On hearing the news of his death the RCD changed the theme of the march to a homage to him and slammed the Algerian government for its “failure” to tackle terrorism.
Algerian newspapers reported shock in Tizi Ouzou on Wednesday, citing local residents fearful that “the machine of evil is in motion”.
There was consternation elsewhere in Africa, too, with French expatriates concerned for their own safety and local people anxious to condemn the killing.
In Tunisia the French embassy has advised its nationals to be vigilant and recommended that they avoid regions near the border with Algeria and with Libya, where Islamist militias are fighting government forces.
An organisation active in the west of the country, Okba Ibn Nafaa, has announced its support for the Islamic State armed group, which recently called on sympathisers to kill nationals from countries supporting the offensive against it in Iraq and Syria.
The interior ministry estimates that 2,400 Tunisians have left to fight against Bashar al-Assad’s regime in Syria and says thousands of others have been presented from doing so.
In Mali, which also shares a border with Algeria, Muslims were anxious to dissociate their religion from the crime, RFI’s correspondents report.
In Niger French expatriates were reported to be “enraged”.
More than 400 military vehicles patrol borders with Mali and Nigeria, where the Islamist group Boko Haram is active.
In Côte d’Ivoire, too, Muslims declared that the murder had “nothing to do with Islam”.
There are 17,000 French expatriates living in the country but the embassy has issued no special security warnings in the last few days.