Reports that 34 have been killed with multiple others wounded after explosions at the city's airport and metro station
1. Suicide attack
At least 14 dead after one confirmed 'suicide bomber' attacked American Airlines check-in desk at Brussels Airport. Two separate explosions went off at Brussels Zaventem airport shortly before 8am, local time. Up to 35 are reported woounded.
Sky News Correspondent Alex Rossi, at the scene of the first blasts at the city's airport, said he heard two "very, very loud explosions".
"I could feel the building move. There was also dust and smoke as well...I went towards where the explosion came from and there were people coming out looking very dazed and shocked."
2. Metro explosion
A second 'terror attack' hit Metro station near EU headquarters shortly after 8am, local time. Reports of up to 20 feared dead after the explosion which took place at a Brussels Metro Station in the Maelbeek area.
Footage of the blast at Maalbeek station showed black smoke pouring from the entrance. Passengers were evacuated from trains in the tunnels around Maalbeek.
Just arrived at Schuman station after walking on the tracks. pic.twitter.com/4xc0YCQmIv— Evan Lamos (@evanlamos) March 22, 2016
Evacuated passengers are being ferried onto buses and are being driven to a 'crisis centre' away from the airport. Brussels Airport has warned people not to visit the scene and have requested all passengers stay away. "Don't come to the airport - airport is being evacuated. Avoid the airport area. Flights have been cancelled," the airport's official Twitter account tweeted.
Authorities shut metro, train, tram and bus services in the Belgian capital following the bomb blasts.
Public transport operator STIB said on its Twitter page: "Bus, tram and metro shut down."
Major rail stations were also closed and Eurostar said no trains would be running to or from Brussels Midi.
The explosion at Maalbeek took place as a train arrived at the metro station during the morning rush-hour.
An Aer Lingus flight that departed from Dublin Airport this morning at 6.40am has reportedly been diverted as a result of the incident. There was a Ryanair flight due to leave Brussels for Dublin at 10.40am this morning. Both airlines operate flights to and from Zaventem airport.
Meanwhile, departures are running normally from Terminal Two in Dublin this morning, with the next flight due to Brussels at 1.15pm.
5. Reaction - "A dark moment for our nation"
"This is a dark moment for our nation. We need calm and solidarity." - Belgian prime minister Charles Michel said in a statement released before 11am.
He added that "there have been many injured."
"The level threat in Belgium has been raised to 4 (maximum alert) with special emphasis on transport hubs, airports, stations and nuclear plants," the statement said.
European Council President Donald Tusk said the Brussels attacks “mark another low by the terrorists”.
EU returns Brussels solidarity now & will help Brussels, Belgium & Europe counter terror threat https://t.co/khlX0qUvqb— Donald Tusk (@eucopresident) March 22, 2016
France is to deploy an extra 1,600 police at its borders in the wake of the Brussels attack, interior minister Bernard Cazeneuve has announced.
“It is essential to maintain a vigilance,” he said in a televised address.
David Cameron has said "will do everything we can to help" Belgium, as security is stepped throughout all European airports. He confirmed he would be chairing a meeting of the Government's COBRA emergency committee later this morning to discuss events in Brussels.
An Taoiseach Enda Kenny Tweeted following the attack: "Once again Europe is under attack. We stand with Belgium. Those using death and violence must and will be defeated."
Once again Europe is under attack. We stand with Belgium. Those using death and violence must and will be defeated.— Enda Kenny (@EndaKennyTD) March 22, 2016