Best News: Brussels Zaventem airport rocked by two explosions

At least 31 people have been killed and many seriously injured in attacks at Brussels international airport and a city metro station.

Twin blasts hit Zaventem airport at 07:00 GMT, killing 11 and injuring 81, Belgium's health minister said.

Another explosion struck Maelbeek metro station an hour later. Twenty people were killed, Brussels mayor Yvan Mayeur said.

Belgium has now raised its terrorism threat to its highest level.

The attacks come four days after Salah Abdeslam, the main fugitive in the Paris attacks, was seized in Brussels.

Prime Minister Charles Michel called the latest attacks "blind, violent and cowardly", adding: "This is a day of tragedy, a black day... I would like to call on everyone to show calmness and solidarity".

More about the attacks

Live: The latest updates

What we know so far

Crisis information

Eyewitnesses recall explosions

In pictures: Brussels explosions

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European Council president Donald Tusk said: "These attacks mark another low by the terrorists in the service of hatred and violence."

The airport and the entire public transport system in Brussels are closed.

'Blood everywhere'

Two blasts tore through the departures area of Zaventem airport shortly after 08:00 local time (07:00 GMT).

The Belgian prosecutor said "probably a suicide bomber" was involved.

The state-owned Belga news agency reports that shots were fired and shouts in Arabic were heard before the two explosions.

Public broadcaster VRT said an assault rifle was found next to a dead attacker. Private broadcaster VTM added that an unexploded bomb belt had been found. Reports say it will be detonated safely soon.

Images on social media showed panic as people fled the airport.

Zach Mouzoun, arriving on a flight from Geneva, told France's BFM television: "It was atrocious. The ceilings collap sed. There was blood everywhere, injured people, bags everywhere. We were walking in the debris. It was a war scene."

All flights have been diverted. Eurostar has cancelled all trains to and from Brussels. The Thalys France-Benelux train operator says the entire network is closed.

Gaps in intelligence - By Chris Morris, Europe correspondent

European security experts had been braced for another attack for months. But it is always a huge shock when it actually happens.

If this was "revenge" for the arrest of Salah Abdeslam on Friday, it will be a source of considerable concern that a functioning terrorist network was able to respond so quickly and with such devastating effect.

It is possible that a cell linked to Abdeslam brought forward the timing of a future attack because they thought he might blow their cover.

Either way, it shows how advanced the planning was in terms of lo gistics, explosives, weapons and people willing to carry out such attacks on civilian targets.

The priority now will be to ensure that anyone else who poses an imminent threat to the public is apprehended as soon as possible. But it is clear that there are still huge gaps in intelligence, and Brussels is seen as a soft target.

In the words of French President Francois Hollande, the response from Europe will need to be "calm, lucid and determined" - and it will have to last for a long time.

Security has been stepped up at Gatwick and Heathrow airports and the UK Foreign Office has advised British nationals to avoid crowded areas in Belgium. UK PM David Cameron chaired a meeting of the Cobra response committee on Tuesday.

France has stepped up security, and the cabinet has held an emergency meeting.

"The terrorists have struck Belgium but it is Europe that was targeted. And it is the whole world that is concerned with this," said French President Francois Hollande.

There is also extra security at Dutch airports.

The metro blast occurred shortly after 08:00 GMT during the rush hour at Maelbeek station.

It struck the middle carriage of a three-carriage train while it was moving away from the platform.

Alexandre Brans told AP: "The metro was leaving Maelbeek station when there was a really loud explosion. It was panic everywhere. There were a lot of people in the metro."

As well as those killed, Mr Mayeur said more than 100 people had been injured, 17 of them severely.

The station is close to EU institutions. The European Commission, the EU's e xecutive arm, has told employees to stay indoors or at home. All meetings at EU institutions have been cancelled.

Ryan McGhee, a catering worker at a college in Brussels, told the BBC: "The entire city is in lockdown. People are calm at the moment but the atmosphere is tense."

Belgium's Interior Minister Jan Jambon had said on Monday that the country was on the highest level of alert for possible revenge attacks after the capture of Salah Abdeslam.

He told Belgian radio: "We know that stopping one cell can... push others into action. We are aware of it in this case."

Zaventem airport is 11km (7 miles) north-east of Brussels and dealt with more than 23 million passengers last year.

Are you at Zaventem airport in Brussels? If it is safe for you to do so please share your eyewitness accounts to haveyoursay@bbc.co.uk.

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