... that would be mon oeuf. What we are talking about here is manœuvre. When you don't know what word you are listening out for, these things sometimes get confusing.
This morning the pompiers were on manoeuvre, having a training exercise in our neighbour's barn. First a pompiers' car arrived, then there was a sound like a shotgun being fired - this, I assume was a smoke bomb being let off. A couple of mintes later a van arrived followed by a firetruck. There was a bit of milling around for 45 minutes or so, then they all packed up and went away.
be selling Chinese lanterns for Bastille day