Two blasts took place at main hall of Zaventen Airport and a third blast hit a metro train in Brussels. The blasts were undertaken by ISIS.
It is said that ISIS has undertaken blasts because of following reasons:
1. Brussels is the capital of Belgium and Belgium is part of NATO fighting ISIS in Iraq and Syria.
2. The headquarters of both NATO and EU are located in Brussels.
3. Few days ago Salah Abdeslam the prime suspect in Paris terror attack was held in Brussels.