This is an interesting firsthand video report of Muslim intimidation of a Coptic Christian church in Egypt by a nearby mosque. As the video points out, someone in the mosque is using the loudspeakers mounted in the minaret to broadcast a rather loud message every 15 seconds or so for the duration of the prayer service going on in the Church. As the video also points out, this interruption is happening outside of one of the five daily calls-to-prayer that the same minaret broadcasts: