Police turned on sirens and flashed behind me.

Good morning! Was driving down a long straight quiet 50mph yesterday, set my cruise control at 60mph. (So car was doing 58mph on Waze)

Anyway a marked police car came up behind me (which looked normal because it was dark), then they suddenly turned their blues on, got up my arse and flashed me. then they overtook me but didn't speed off that fast, they went maybe 60mph while I slowed all the way down to 40mph. So I made quite a gap between us before he turned off at a roundabout and I went the other way.

Was I meant to follow him? Surely if I was they would of displayed the "FOLLOW ME" sign or at least made a signal / gesture?

I'm guessing it was just a warning to slow down without having to give me a ticket and he was on the way to a more important call?

Cheers!