Question: did the trains in Norway also stop when Hamas was sending thousands of Quassam rockets at Israeli civilian areas over the past few years, or does this sort of protest only get triggered when Jews are using weapons?
Long answer: If you are asking others for objectivity, please be objective yourself. The issue here is that nowadays a lot of people in Europe tend to be on the side of the underdog, which in this case would be the Palestinian population. This is not a pro-Hamas demonstration. Nobody likes fanatics here.
If Israel were in the weaker position, I can assure you that the same people would stop the trains for Israelis.