Security forces have arrested dozens of people in Algeria only two days after 22 people were killed in ethnic clashes between Berbers and Arabs in the southern city of Ghardaia.
Ghardaia is situated in the M'zab valley, a UNESCO world heritage site on the edge of the Sahara which has seen growing tensions between the two ethnic groups.
According to the prime minister, 27 people were arrested over suspected involvement in the violence in Ghardaia. Independent sources say the number of suspects who were detained is over 35.
Algerian Berber rights activist Kamal Fakhar al-Din is among those who were arrested.
Fakhar al-Din was in a mosque in Ghardaia before security forces stormed in and arrested him and several other people.
Sixteen out of the slain 22 were Berbers.
Barricades of tyres and wheel barrows were placed between rival neighbourhoods and tribes. Homes, shops and cars were also torched, the AFP news agency reported on Thursday.
Ghardaia has seen violent clashes for the last two years between Arab and Berber rivals, but the latest incident was one of the worst seen so far.
The deadly clashes took place in Ghardaia and two other nearby cities, Guerrera and Berianne.
The APS news agency reported that police tried to suppress the clashes, while violence continued as rioters targeted shops, automobiles and public buildings.
Ghardaia has experienced ethnic unrest between members of the local Berber community, known as Mozabites, and Algerians who speak different languages and follow a different school of Islam.
The two groups have been fighting over limited jobs, land and housing in the poor region.
Tensions increased in the region after a Mozabite cemetery was desecrated in December 2013, causing clashes which left hundreds of people injured and caused the led to the deaths of dozens.