France has expelled 12 Algerian diplomatic officials in what it describes as a “symmetrically” measured response to Algeria’s earlier removal of 12 French representatives, deepening the already strained relations between the two countries.

Algeria had announced the expulsion of the French officials on Monday, citing the arrest of one of its consular staff by French authorities.

The official was implicated in a kidnapping case, but tensions between Algiers and Paris had been building long before the incident.

The diplomatic fallout traces back to France’s policy shift last summer in favor of Morocco’s autonomy plan for Western Sahara—a move that angered Algeria, which backs the pro-independence Polisario Front in the disputed region.

Relations worsened again in November after the Algerian government detained French-Algerian writer Boualem Sansal, a prominent critic of Algiers.

As part of its retaliatory move, France not only expelled the 12 Algerian officials but also recalled its ambassador to Algiers for consultations. A statement from the French presidential palace on Tuesday accused Algerian authorities of being responsible for “a brutal deterioration in our bilateral relations.”

The backdrop of the latest tit-for-tat expulsions includes an ongoing investigation by French counterterrorism prosecutors.

Three Algerian nationals, including the detained consular official, were recently charged with “kidnapping or arbitrary detention … in connection with a terrorist undertaking.”

The suspects are believed to be linked to the abduction of Algerian influencer Amir Boukhors, also known as Amir DZ, who is a vocal critic of the Algerian regime and commands a large online following of over 1.1 million on TikTok.

This flare-up in tensions comes shortly after what seemed to be a thaw in relations. French President Emmanuel Macron had reached out to Algerian President Abdelmadjid Tebboune just two weeks ago, with both sides reportedly agreeing to mend ties and revive cooperation.