The UK Foreign Office advised British nationals to avoid crowded areas in Belgium following the two blasts that tore through the departures area of Zaventem airport on Tuesday, the BBC reported.

Security has also been stepped up at Gatwick and Heathrow airports following the blasts.

Earlier, UK PM David Cameron said he is "shocked and concerned" after a series of deadly bomb blasts in Brussels.

The UK "will do everything we can to help" Belgium, he said.

The second explosion hit Maelbeek metro station, close to the EU institutions. The airport and whole transport system in Belgium have been closed.

Source : MENA