The Hiroshima attack made the front pages of newspapers globally. It was considered a major event, not just for the war (which was front-page news globally) but also for the future of humanity: the discussion immediately leaped from the specifics of Hiroshima to the generalities of nuclear warfare. This was encouraged by the information that was released by the United States on the atomic bomb. So in this sense the atomic bomb was meant to be "universal": it was not meant to be about the use during the war, but also about its long-term implications. I cannot speak of all newspapers but it was clearly covered in Commonwealth countries (e.g. India, Australia, the UK) very extensively, in no small part because the UK and Canada were partners on the atomic bomb project.

Nagasaki made headline news of course as well, but was in many places overshadowed by the news that the Soviet Union had entered into the Pacific War and begun their Manchurian invasion.

I don't generally answer "how did people react" questions because there are just too many people in the world to answer for everyone, and different countries had different trends of opinion, and we only have good evidence from a few of them. But any country that had war news generally had some coverage of the atomic bomb. It was, in some cases, somewhat minimal: in the Soviet Union, state-controlled presses barely discussed the atomic bomb, because Stalin did not want it to be a major factor in the minds of Soviet people while the USSR lacked one.