An Algerian court upheld on Tuesday a five-year prison sentence being served by French-Algerian writer Boualem Sansal for undermining national unity, Ennahar TV said, prompting a call for clemency by France.

The conviction of Boualem Sansal, an outspoken French and Algerian writer, has worsened tensions between the countries.

Sansal was first sentenced on March 27 on charges related to undermining Algeria's territorial integrity over comments made to a French media outlet.