A mob, outraged by reports that Islam’s holy prophet had been insulted, burned down a house in northwest Nigeria 22 Aug., killing eight people inside.

Police confirmed the incident, the news organization This Day reported. It began when a student of Abdu Gusau Polytechnic school in Nigeria’s Zamfara state was alleged to have insulted the prophet while talking with a Muslim fellow student. A group of angered students beat the man, whose name has not been released. Nigerian news organization Premium Times cited a resident of Talata Marafa town, where the school is located, as saying the victim was a convert to Christianity.

Other students took the victim to hospital, but he was retrieved and returned to town by the friend of his sister, Premium Times reported. The mob, spotting the car that had been used to transport the victim, burned it and a nearby house, where eight people were inside. Newsweek reported that it’s not clear whether the student accused of blasphemy was in the house.

Police declared a curfew. Nigerian President Muhammadu Buhari condemned the attack.

Insults to Islam are not illegal in officially secular Nigeria, which is mainly Muslim in the North, and Christian in the South. But allegations of blasphemy have prompted deadly violence in Nigeria this year. On 30 May, 24-year-old Methodus Chimaije Emmanuel was killed by a mob in Niger state, after he allegedly posted a blasphemous statement on social media. Three days later, Bridget Patience Agbahime, 74, was killed by a mob for an alleged insult to Islam — charges that witnesses said were baseless.