'raise the alarm' is not too common.
but 'sound the alarm' or 'trigger the alarm' would be used in AmE if there was literally some alarm system that could be activated to warn people. If the people are warning other people we might say "Neighbours warned each other when they smelled smoke." or "Neighbours alerted each other when they smelled smoke." Instead of the BrE "Neighbours raised the alarm when they smelled smoke."
- For Teachers