They are the peregrines who nest on Norwich cathedral with their chicks from last year.
Yesterday I was in Norwich to visit the cathedral. I always go in the back way to avoid the information desk staring at me about not donating for my visit,. I prefer to support by regularly stocking up
on very specific soap which they have in the cathedral shop. As I was going through the carpark there were a lot of peregrine-like birdcalls and I realised that the two Norwich residents were hanging around the nest ledge. Bit early for eggs but I presume they are claiming territory for later (yes that was taken with a zoom).