Back in the day working on land seismic crews our blasting was handled by radio signal transmitted from the observer doghouse to the blaster at the shot-hole. You could hear on the radio when the recording crew began shooting for the day's production. There was a tone that triggered the shot while the blaster was connected to the blasting cap on the down-hole charge.

If someone placed explosives in a radio device I'm sure it would be quite easy to detonate them on command with a signal tone.