Francis led a prayer for the dead Sunday when he greeted a crowd of faithful in St Peter's Square. He says he is also praying that the international community's efforts toward building peace find support.
The pope says of the victims: "May the Lord welcome them into his house."
At least 28 people died last week in the attack by al-Qaida-linked extremists on a hotel and cafe in Burkina Faso's capital, Ouagadougou.
Eight others perished in a suicide bombing and gunfire attacks by Muslim militants in Jakarta, Indonesia.