Early on Tuesday morning Brussels was hit by three explosions, with one involving a suicide bomber.
More than 30 people are believed to have been killed, while as many as 200 are thought to have been injured in the attacks.
Twin blasts hit Zaventem airport at around 8AM GMT (8PM New Zealand time). This killed 11 people and injured dozens.
Another explosion hit Maelbeek metro station an hour later, leaving a further 20 dead.
The metro station is very close to the EU headquarters.
Victims caught up in the attacks
Islamic state (IS) have claimed responsibility for the attacks in a statement released through their new agency, Amaq.
An unexploded suicide vest and Kalashnikov rifle was also reportedly found at the airport, and a controlled explosion of a suspicious package was also reportedly conducted at the airport too.
Brussels police have issued a CCTV image of three men said to be suspects in the attacks.
They have also issued a wanted notice for a man seen pushing a luggage trolley through the airport who is thought to have survived the attacks.
Belgium has raised its terrorism alert to its highest level, and three days of national mourning have been declared.
Prime Minister Charles Michel said: “This is a day of tragedy, a black day…I would like to call on everyone to show calmness and solidarity.”
The scene from the airport after the attack
Why was Belgium attacked?
This comes just four days after the capture of Salah Abdeslam, a suspect in last year’s Paris attacks. He was captured from a Brussels suburb last week, and there was a threat of a revenge attack following his arrest.
Security in the rest of western Europe has been stepped up, and many of the countries security committees are meeting to discuss the attacks.
No Kiwis are reported to have been caught up in the incidents.
