VRT say that the attack at the airport was a suicide bomb and that 13 are dead and 35 injured.
The European Commission has told all its employees to stay at home on in their offices.
Some passenger photos from Brussels airport
All public transport closed in Brussels
Multiple unconfirmed reports of a fourth explosion in Brussels, at a Metro station.
Brussels' main railway stations also now closed.
Increased security being reported in Paris airports and stations as well as at London's Gatwick airport.
Reports of 23 dead in Brussels attacks
Belgian broadcaster VRT says that no-one was killed in the explosion in the Brussels metro but conflicting reports coming from a police officer quoted by AFP.
Belgian prosecutor confirms Brussels blast was a suicide attack - (Broadcaster RTBF)