Both massacres' official numbers are highly disputed, so can't really say which killed more, though most likely 1919. Secondly 1919 was against non-violent civilians, 1984 was against armed militants.
Geographically, the same. Politically, they may as well have been on different planets. If from what I have read is correct, it was civilians in 1919, not so much so in 1984. I don't think the UK need to apologise for either so I bid you adieu
Oh and surviving 'civilians' of 1984 and their compatriots were subsequently responsible for the largest mass killing in Canadian history, which was also the world's most destructive act of aviation terrorism until 9/11 ... Air India Flight 182 - Wikipedia