President Erdogan says Brussels ignored Turkey's warning last year on one of the terrorist attackers

Police in Brussels on Thursday ramped up a desperate hunt for a fourth man suspected of taking part in the Islamic State bombings that struck at the very heart of Europe.

European security authorities faced mounting pressure after it emerged that two brothers who blew themselves up at Brussels airport and a metro station were known to police and that one of them had been deported from Turkey as a "foreign terrorist fighter".