The first and foremost measure that a government needs to take is to supply medical emergency equipment to the place where an act of terrorism has been conducted. Then comes the investigation part, in which each and every individual who could remotely have any link with the terrorism should be investigated.
While many people especially the ones who are innocent may not appreciate this, but the truth is that such investigations need to be conducted for the better good. In the end, those who are found guilty or accountable should be treated with the punishments they deserve so as to show a lesson to the world.