Reference for Taanit 27:13

במאי אילימא בשופרות שופרות בשבת מי שרי אלא לאו בעננו וקרי לה התרעה ש"מ:

The authority who says that the recital of the 'anenu constitutes the sounding of an alarm [will hold] how much more so does the sounding of the shofar, but the authority who says, 'by the shofar', would exclude the recital of the 'anenu. But has it not been taught: In the case of all other visitations that break out [in the world], as for example.

Jastrow