At least 10 people have been killed and several injured after two explosions ripped through Zaventem Airport in Brussels.
Shots were fired and Arabic shouted before the blasts, according to Belgian news agency Belga, as there were fresh reports of an explosion at Maalbeek metro station in the city.
The country's public broadcaster RTBF said there were several fatalities.
Confused and shocked passengers fled the terminal to safety as they were evacuated by armed police.
According to reports the suspected terror attack centred on an American Airlines desk in a departure hall at around 8am
Airport spokeswoman Anke Fransen said: "There were two blasts in the departure hall. First aid team are in place for help."
A police official added: "One person has died and perhaps there are several more."
The attack comes as the Belgian capital is on high alert following the dramatic arrest of Paris attacks suspect Salah Abdeslam in the city last Friday.
Sky's Alex Rossi, at the scene, said: "I was in the duty free in Zaventem Airport and I 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.
"The thinking here is that it is some kind of terrorist attack although that hasn't been verified by any of the authorities here at the airport.
"Don't know how the explosion took place, the method if you like. But it certainly seems Brussels airport has been targeted in a terrorist attack.
"We are all being moved out of the airport now towards the emergency exit.
"There is a great deal of confusion here. Certainly there are a number of very upset, as you might imagine, very frightened people."
He added: "There are fears that there might be other attackers."
All trains have been suspended to the airport which has been closed until further notice
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