“The incident itself was sparked by the circulation of a rumor within the village’s Muslim population that church officials were installing a bell. This led to villagers with extremist views to incite the village’s Muslims to attack the church.”
That’s not “extremist views,” that’s mainstream Islam. Islamic law forbids the subjugated People of the Book (Jews, Christians, Zoroastrians) to make public display of their religious festivals, including the ringing of bells. The dhimmis “are forbidden…to ring church bells or display crosses…recite the Torah or Evangel aloud, or make public display of their funerals or feastdays” (Reliance of the Traveller, o11.5 (6).)
If they violate these laws, they can lawfully be killed.
Meanwhile, why were three Christians arrested? Were they helping to destroy the church? Or were they arrested because Egyptian authorities were engaging in a bit of victim-blaming and targeting the Christians who fought back? The latter possibility is much more likely.
“Police arrest 17 suspects in Coptic Church attack,” Egypt Independent, December 24, 2017:
Security forces in Giza arrested 17 people on Saturday on suspicion of participating in the mob of hundreds which stormed the Church of al-Amir Tadros (Prince Tadros) on Friday in Giza’s Atfeeh area village, Kafr al-Waselin.
Giza security sources said that arrested suspects will be prosecuted on accusations of thuggery, vandalism, rioting, and stirring sectarian strife between Muslims and the minority Coptic Christians.
Among those arrested, 14 were Muslim, and three were Christian.
The Archbishop of Atfeeh said on Friday that a mob gathered outside the church at noon on Friday, chanting hostile slogans demanding the demolition of the church, before storming the site.
The incident itself was sparked by the circulation of a rumor within the village’s Muslim population that church officials were installing a bell. This led to villagers with extremist views to incite the village’s Muslims to attack the church.
Police sources said that after Friday prayers, approximately 80 local Muslims moved towards the church, threatening to destroy the church if the bell was installed.
The mob smashed chairs, destroyed much of the church’s interior contents, and assaulted Christians who were present, before security forces were able to step in.
An official source at the Giza Security Directorate revealed that the church was established in 2002 after an agreement between the village’s Muslim and Christian populations, on the condition that it would be a small building for prayer, without a crucifix on display, not a dome, a bell, or a beacon….