Austria’s Catholic bishops have appealed for prayers for the victims of Monday night’s Islamist terror attack in Vienna.

Gunmen opened fire at six different locations in the Austrian capital, killing at least four people and injuring 17 others.

Archbishop Franz Lackner, president of the Austrian bishops’ conference, said that the attack was the result of a “misguided, inhuman ideology.”

“Believers must condemn this act in the name of God, and inwardly resist it with all their strength of spirit and faith,” the archbishop of Salzburg told Kathpress.

The shootings came after several days of Islamist attacks and demonstrations against Catholics and Catholic churches in Austria.

A 19-year-old Afghan was arrested Monday, and has confessed to striking a religious sister, 76, in the face on Saturday afternoon as she rode a bus in the Austrian city of Graz.

Between 30 and 50 young people also attacked a church in Vienna-Favoriten on Thursday evening, shouting “Allahu Akbar,” and kicking pews and other furnishing in the church.

Another Afghan was arrested over the weekend while shouting “Islamic slogans” in St. Stephen’s Cathedral, Vienna police confirmed.