Brussels on high alert after deadly explosions

[Updated] A double suicide attack at Brussels Airport and another explosion at a metro station have left at least 13 people dead and forced the closure of the city's public transport network.

The Belgian government has raised the threat alert to the highest, level four, across the country.

Belgium's prosecutor said two suicide attackers struck at Zaventem airport on the outskirts of the city, killing at least 13 people and injuring 35 more.

Another blast caused casualties a...