In both locations, crowds sing 'God save the King' as the band plays, before giving three cheers.
Earlier, Charles III swore an oath and paid tribute to the late Queen at a meeting of the Accession Council.
Prince William, Queen Camilla, serving politicians and former prime ministers were in attendance.
A wave of further proclamations will take place across the UK until Sunday.
The Queen, the UK's longest-reigning monarch, died peacefully at Balmoral Castle on Thursday afternoon at the age of 96.