An Egyptian judicial official says a criminal court has convicted three Christians of killing a Muslim man in a dispute that set off some of the country's worst sectarian violence this year and left nine dead.

The official said the court sentenced one Christian man to life imprisonment, and two others to 15 years for killing a Muslim resident of Khosoos, a town north of Cairo in April. The official, speaking on condition of anonymity because he was not authorized to speak to reporters, said nine Muslims were sentenced to up to five years for vandalizing Christian properties.

No one was tried for the death of at least six Christians.

The violence was sparked by an argument when locals accused Christians of desecrating an Islamic school, a charge they denied.