GHARDAIA, Algeria: Algerian authorities have arrested 38 people in connection with deadly ethnic unrest between Berbers and Arabs in the south of the country, police and the gendarmerie said Friday.

Police also said a hunting rifle, knives and Molotov cocktails were seized during a probe into unrest in the southern province of Ghardaia that left 22 people dead Tuesday.

Police said 27 people had been detained Thursday “for harming public order, citizen’s security and property.” State television, citing the gendarmerie, said 11 more people were rounded up, bringing the total to 38.

Algerian media reported that masked gunmen went on a killing and arson spree in the town of Guerara Tuesday night and into the early hours of Wednesday.

Guerara is in the M’zab valley, a UNESCO World Heritage site on the edge of the Sahara desert, where tensions between Mozabite Berbers and Arabs have flared on and off since December 2013.

But it was the first time firearms were used in confrontations between members of the two communities. That and the highestdeath toll in years has prompted President Abdelaziz Bouteflika to order the army to move into Ghardaia and restore order.

Prime Minister Abdelmalek Sellal toured the province Thursday, saying the government was determined to take “appropriate and firm action” and that the army had been given “all the necessary powers to re-establish order.”

Families of the victims were still waiting Friday for authorities to hand over the remains of their loved ones for burial. The bodies have been taken to state morgues where forensic experts are carrying out autopsies.

The Mozabite Berbers are followers of the Ibadi faith, an austere form of Islam that predates the split between Sunnis and Shiites. The Chaamba Arabs, like the majority of Algerians, are Sunnis.