WHAT WE KNOW SO FAR
- More than 30 people have been killed and over 100 injured in twin attacks on Brussels airport and a rush-hour metro train in the Belgian capital on Tuesday
- Shots were reportedly fired at the airport and there were shouts in Arabic shortly before the blasts, according to witnesses
- At least 11 people were killed in the airport blast and 81 wounded (Belgian health minister)
- Brussels mayor says at least 20 were killed on board the metro train and more than 100 injured at the Maelbeek subway station near the European Union headquarters
- A terror alert has been issued in Europe; U.S. airlines diverted and canceled flights to and from Belgium
- Brussels was already on a state of high alert following the arrest of Paris terror suspect Salah Abdeslam in the city last week
