The IRA put bombs in pubs and Burger Kings, with nothing resembling a "warning" issued and with there being little point in planting them unless the aim was to kill civilians, primarily or secondarily.
Frankly I'm tried of hearing people on this side of the Atlantic give them a pass simply because they were made up predominantly of Christians and because their cause is sympathetic. They were (and the remaining pockets who've continued to fight since the peace agreements of the 1990s still are) murderous thugs. At best, you can argue they weren't as lethal, with fewer people killed and with no attempt to drag in unrelated countries into their bitter dispute. But yes, as a Brit living in Britain for the first 25 years of my life, there was a target on my back - not as big as it was for soldiers, police, and everyone from construction workers to bankers considered by some arbitrary definition to be helping the British in Northern Ireland, but it was there.
The IRA did not appear out of a vacuum. They were a response to the systematic abuse of the native Irish by the British. They may have been nasty but they were in no sense religiously motivated. As usual, one person's freedom fighter is another person's terrorist.