Based upon past experience, the games would continue.
There was a terrorist attack in 1972 on the Israeli delegation to the Munich games. That attack held hostages and unfolded of a long period of time, and the games continued, albeit delayed while the drama unfolded. In 1996, in Atlanta there was a bombing, but it didn't stop the games.
The only way that it might stop the games would be if the attack were sever enough to prevent the tournament from actually occurring, in a meaningful way. For example, if one or more team were to be functionally eliminate (captured or killed) it might have to cancel the games. Similar events have occurred, such as the Andean Flight Disaster, which killed or stranded all the members of a rugby team. On the other hand, when all of the players of Marshall University were killed in an aircraft accident after the final game of the season the University still fielded a team the next year, although obviously, a year's gap allows for a lot of recovery.