This is quite awful. Takes me back to the days of the IRA bombings which came out of nowhere and happened at any time. They don't seem that long ago to me, I was working in central London on the day of the Bishopsgate bombing and had actually directed two elderly American tourists to that vicinity in the morning, they were a bit confused by an underground map and I was trying to be helpful. I always remember them and hope they were not in the wrong place at the wrong time.
We were constantly on our guard. Avoided unattended packages. All refuse bins on stations and elsewhere were sealed shut. The news was constantly reporting terrorist bombings.
I hope it doesn't progress to all that but the fact is, if a minority group is unfairly vilified and stereotyped, as now in the media (& all over facebook), they will band together and become militant. That has happened throughout history.
Why the human race cannot live together harmoniously, respecting each other's differences, is beyond me. We are all human beings first and foremost.