Ukrainian president has expressed his concern by the events in Brussels
"Shocked by deadly terrorist act in heart of united Europe. Condolences to Families of victims. We must stop terrorism together", - has written Petro Poroshenko on Twitter.
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Two explosions tore through Brussels airport on Tuesday morning killing 13 people in a suicide attack, and a further blast struck a metro station in the capital shortly afterwards.There are unconfirmed reports that 23 people have been killed in both attacks.
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All public transport in Brussels was shut down, as it was in London during 2005 militant attacks on the underground that killed 52. The Belgian Crisis Centre, clearly wary of a further incident, appealed to the population: "Stay where you are".
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The blasts at the airport and metro station occurred four days after the arrest in Brussels of a suspected participant in November militant attacks in Paris that killed 130 people. Belgian police had been on alert for any reprisal action.