UPDATE: There is now a report from the BBC of an explosion on the Brussels Metro (Maelbeek metro station) close to the buildings that house the European Union offices.

The day after the arrest of someone alleged to be involved in the Paris bombings, it appears that there may have been an attack on Brussels airport this morning. The BBC, and other news outlets in the UK report two explosions and there are some reports of casualties. Up to 13 people are reported dead now.

The airport is apparently closed to traffic and is being evacuated. Train, bus and metro services to the airport are also suspended.

The latest BBC report is here. Their live coverage is here – there are some distressing images.

The whole of the Brussels Metro system is closed down, according to a tweet they have sent.

One report states that the explosion was close to the AA check-in desks as well as Brussels Airlines, but the BBC has no confirmation. In addition the Belgium Government confirms casualties with one news agency reporting the discovery of more bombs during a search of the airport.

There is a video on Twitter showing broken windows and smoke rising from the terminal buildings. There is another taken from a car park showing passengers running away from the scene.

British Airways has cancelled its flights this morning: