As part of their security measures, many places of worship are considering lockdown systems so that if there is a threat of an imminent attack there can be a site wide alert and all places of entry can be locked.  The Alertex wireless critical alert system is already widely used in the education sector and require no cabling or WiFi connection.  With a long transmission range of 1km, when one Alertex unit is triggered it will activate all other Alertex units in range with a sounder and flashing blue beacon which differentiates it from a fire alert.  There are voice annunciators available allowing warnings to remain inside to be made in a number of languages if required.  Key staff can also utilise the mobile panic alert key fob which when triggered will activate all Alertex units within range.