Herve Gourdel: Algeria in shock over beheading
Algeria is in shock following the beheading of French tourist Herve Gourdel.
Security has been stepped up in the capital, Algiers and police are patrolling the city's main thoroughfares and parks.
Their presence is worrying the city's residents, who fear the possibility of a militant attack.
"Heinous, inhuman, barbaric, cowardly, criminal, despicable" are among the words that keep coming up in conversations in cafes, on the street, and social networks.
The sense of shock is especially deep in the Kabylie region, where the killing occurred.
It has increased the feeling of fear in Kabylie. The mountainous region has suffered at the hands of militants in recent years.
Since the late 1990s, it has been the main stronghold of the militants who later formed al-Qaeda in the Islamic Maghreb (AQIM).
'Avoid roads at night'
Attacks on both security forces and civilians, fake roadblocks, kidnappings, and raids on villages are common across the region.
Residents say they avoid the roads at night - unless when they absolutely have to travel.
Since the end of 2005, more than 80 shop-owners, businessmen and industrialists have been abducted by armed groups in the Tizi Ouzou area alone.
Three have been killed; the others have been freed, either as a result of ransom being paid or residents mobilising and putting pressure on the kidnappers.
The Kabyle Berbers - who are known for their hostility towards the Algiers authorities - are blaming the government. They accuse it of abandoning the region to Salafist militants.
AQIM had recently shifted its focus to the desert region of the Sahel, on Algeria's southern borders.
But continuing insecurity in Kabylia keeps prospective investors away. A number of businesses that were based in the region for years have been driven away by armed Islamist groups.
The government has strongly condemned Mr Gourdel's killing, which is a huge blow for Algeria.
The incident damages official claims that the country is stable, relatively safe, and that its militants have been crushed.
It also casts doubt on the olive-branch policy pursued by President Abdelaziz Bouteflika since his election in 1999.
Armed groups in the country are among the beneficiaries of an amnesty under a "Charter for Peace and National Reconciliation" in force since 2006.
That policy had already been dented by the January 2013 attack on the gas complex at In Amenas, near the Libyan border, in which 67 people - including 37 foreigners - were killed.
The latest attack, allied to the Tunisian crisis and the chaos in Libya following the ousting of Colonel Muammar Gaddafi, only increases concerns about the security situation in Algeria.
Jund al-Khilafa (Soldiers of the Caliphate), the group that said it killed Mr Gourdel, is not new.
It was one of the battalions of AQIM, before it announced that it had joined Islamic State (IS) earlier this month.
It has been active in recent years in Kabylie's Djurdjura mountains.
Who are Jund al-Khilafa?
- Previously part of al-Qaeda in the Islamic Maghreb (AQIM), which grew out of Algerian Islamist groups involved in 1990s civil war
- Carried out numerous attacks in Kabylie region - in April, ambushed an army convoy, leaving 11 soldiers dead
- Many residents have fled the region's forests and mountains in recent years because of insecurity
- Group said to be led by Abdelmalek Gouri, known as Khaled Abou Slimane, 37
- On 14 September, pledged allegiance to Islamic State
Its most recent attack, committed under the banner of AQIM was on 18 April when it ambushed an army convoy, killing 11 soldiers in the same area where Mr Gourdel was kidnapped on Sunday.
The launch of IS in Algeria could prove to be the end of AQIM in the country - it has been virtually silent for some time.
Civil war massacres
A new Islamist manifestation would continue a long trend in Algeria, since militant groups first emerged in the 1980s.
Several different groups fought in the civil war which ravaged the country after the army annulled the 1991 elections, with the Islamic Salvation Front (FIS) poised to win.
The Armed Islamic Movement (MIA) turned into the Armed Islamic Group (GIA), which in turn became the Salafist Group for Preaching and Combat (GSPC).
The GSPC was then central in the creation of AQIM, which has since spread to several neighbouring countries.
But judging by its actions since its brief existence, Jund al-Khilafa could turn out to be the most brutal of them all.
During the civil war, the GIA use to massacre entire villages by slitting the residents' throats.
Algerians are hoping not to revisit the horrors of those dark days.