"We believe that this unprecedented event in your country will draw a great sign of fraternity in the Algerian sky to the whole world," Francis wrote in a greeting in French, the language of the former colonial power France still widely spoken in the mostly Muslim country.
The martyrs included Pierre Claverie, the bishop of Oran who was killed in a 1996 attack during the Algerian civil war.
The list of martyrs also includes seven monks who were kidnapped and killed by Islamist extremists in the same year.
The 19 people were all killed "out of hatred for faith," Pope Francis said on Saturday in St Peter's Square in the Vatican.
The beatification was held in Oran's Catholic Church of Santa Cruz.
Algerian Minister of Religious Affairs Mohammed Aissa, who attended the ceremony, called it an "important" event.
"The Algerian constitution safeguards the freedom to practise religious rituals for non-Muslims," Aissa said, according to the state-run Algerian Radio.
The Catholic Church's procedure of beatification constitutes the first step towards becoming a saint.
The martyrs included Pierre Claverie, the bishop of Oran who was killed in a 1996 attack during the Algerian civil war.
The list of martyrs also includes seven monks who were kidnapped and killed by Islamist extremists in the same year.
The 19 people were all killed "out of hatred for faith," Pope Francis said on Saturday in St Peter's Square in the Vatican.
The beatification was held in Oran's Catholic Church of Santa Cruz.
Algerian Minister of Religious Affairs Mohammed Aissa, who attended the ceremony, called it an "important" event.
"The Algerian constitution safeguards the freedom to practise religious rituals for non-Muslims," Aissa said, according to the state-run Algerian Radio.
The Catholic Church's procedure of beatification constitutes the first step towards becoming a saint.