Brussels main airport failed to reopen on Friday evening as planned because police and airport authorities could not agree on how to screen passengers arriving for flights following the March 22 suicide bombings.

Brussels airport will partially reopen for passenger flights on Friday evening after its closure following the March 22 bomb attacks, the company running the airport said.

Bomb-damaged Brussels airport held a drill for a partial restart on Tuesday but warned it could take months to reopen fully.

Brussels airport will not reopen before Tuesday as it implements new security measures and repairs the departure hall wrecked by a suicide bomb attack earlier this week, it said Saturday.

Belgium's federal prosecutor confirmed that Najim Laachraoui was one of the two suicide bombers who struck Brussels airport this week in a series of attacks which left 31 people dead.

Belgian police were hunting for a "third man" filmed with two Islamic State suicide bombers at Brussels Airport as investigators accumulated evidence that the same jihadist network was involved in the Paris attacks.

Belgian police identified two suspected Islamic State suicide bombers captured on security cameras before they struck Brussels Airport in the first of two attacks that also hit the city's metro, public broadcaster RTBF said.

Several countries have tightened or reviewed airport security following twin explosions at Brussels Airport, as Australian Prime Minister Malcolm Turnbull blamed Europe's porous borders and lax security for the attack.

The Belgian capital was on lockdown Tuesday following deadly explosions at Brussels airport and on a metro train which killed more than 30 people and wounded over 200.

European countries on Tuesday vowed to defend democracy against terrorism after blasts at Brussels airport and in the EU's institutional heart left around 35 dead and more than 200 injured.

A series of apparently coordinated explosions ripped through Brussels airport and a city metro station Tuesday, killing at least 26 people in the latest attacks to target Europe.

Explosions tore through the departure hall of Brussels airport on Tuesday morning killing one person and injuring several others, the Belgian news agency Belga said.