EU leaders have been quick to respond to the attacks in Brussels with the foreign policy chief Federica Mogherini appealing for "international unity" in tackling terrorism.
The Italian EU official's comments come as Belgium declared three days of mourning in the wake of the terrorist attacks on Tuesday that killed 34 and injured scores of others.
Today, Wednesday 23rd March, people were asked to observe a minute's silence in Brussels at midday in memory of the victims.
Speaking on the second day of a trip to Lebanon and Jordan, Mogherini, the EU's High Representative for foreign policy, broke down in tears as she called the attacks a "sad day for Europe."
During an emotional press conference in Amman, together with Jordanian Foreign Minister Nasser Judeh, she said, "Europe and its capital are suffering the same pain that this region has known and knows every single day, be it in Syria, be it elsewhere.
"It is quite clear that the roots of the pain we are suffering around our region are very much the same and that we are united in not only the suffering of the victims, but also in reacting to these acts and preventing radicalisation and violence together. The terrorists will not divide us."
As the manhunt continued for those behind the latest terrorist outrage, European Council president Donald Tusk said he was "appalled" by the bombings which had "cost innocent lives."
The former Polish PM added, "These attacks mark another low by the terrorists in the service of hatred and violence. The European institutions are hosted in Brussels thanks to the generosity of Belgium's government and its people. The European Union returns this solidarity now and will fulfil its role to help Brussels, Belgium and Europe as a whole counter the terror threat which we are all facing."
Elsewhere, a statement issued by the European Council said the EU "mourned" the victims of "an attack on our open democratic society."
It went on, "Our common European institutions are hosted in Brussels, thanks to the generosity of the government of Belgium and the Belgian people. The EU and its member states stand firm with Belgium in solidarity and are determined to face this threat together with all necessary means.
"This latest attack only strengthens our resolve to defend European values and tolerance from the attacks of the intolerant. We will be united and firm in the fight against hatred, violent extremism and terrorism.
Further reaction came from Belgium PM Charles Michel who said, "What we feared has happened."
Meanwhile, the EU institutions extended their advice to staff to work from home if possible, or remain inside buildings as the security alert remained at "orange", or the highest possible.
The city's airport, scene of the first attack by suicide bombers, remained closed Wednesday and the transport network in Brussels was still subject to severe restrictions.
The rush hour bombings came days four days after the capture of Salah Abdeslam, the fugitive wanted in connection with the Paris attacks last November.