Right wing parties across Europe have blamed Tuesday's attacks on EU policies, EUobserver reports., external It says Belgian, British, Dutch, French and Italian Eurosceptics are all trying to score points from the attack.

The UK Independence Party - campaigning for Britain to leave the EU in a referendum in June - published a press release just one hour after the fatal bomb blast in Maelbeek metro station in which defense spokesman Mike Hookem blamed the attacks on the EU's freedom of movement laws and on Germany’s decision to welcome refugees.

Likewise, the Netherlands anti-immigrant politician Geert Wilders - whose Freedom Party leads in national polls - was reported to have called for the West to be "de-Islamisced", while French National Front leader Marine Le Pen is reported to have complained that Islamic fundamentalism "is not being treated like the threat it really is". 

Image source, AFP

A security perimeter remains in force around the Maalbeek metro station in Brussels where about 20 people died in Tuesday's explosion.

Image source, AFP

French Prime Minister Manuel Valls says it is now imperative to tighten controls on the European Union's borders after the bombings in Brussels. 

"There is an urgent need to strengthen the external borders of the European Union," Mr Valls told French radio, adding that heightened vigilance was required to stop people crossing into Europe with false passports, as the group know as Islamic State has "stolen a large number of passports in Syria". 

Image source, EPA

Image source, PA

More about David Dixon, the British computer programmer from Nottingham missing in the aftermath of the attacks. His partner Charlotte Sutcliffe in in Brussels searching for him. Charlotte's sister,Marie Sutcliffe, told the BBC's Today programme of the "heartbreaking" wait for news.

UK Prime Minister David Cameron is to chair an emergency meeting later to determine Britain's response to the attacks. Two Britons were injured in the blasts at the city's airport and metro on Tuesday which left 34 people dead. There are also concerns for David Dixon, an IT programmer from Nottingham, whose family said he had not been seen since the blasts.

Security is being stepped up at airports around Asia, with South Korea, Japan, Indonesia, Thailand and India all saying they are deploying additional resources at major hubs.

Meanwhile, Australian Prime Minister Malcolm Turnbull has cited concerns over Europe's open-borders Schengen passport-free zone, and lax security.

Controls were tightened in the wake of last November's Paris attacks but Mr Turnbull was quoted by Reuters as saying "regrettably they allowed things to slip".

"That weakness in European security is not unrelated to the problems they've been having in recent times," he added.

The Brussels airport suspect still at large has been named as Najim Laachraoui, who was already being sought by police after he was linked to the Paris attacks in November, Reuters reports Belgian newspaper DH as saying. 

On Monday, prosecutors said his DNA was found in houses used by the Paris attackers last year. He was also said to have travelled to Hungary in September with Paris attacks suspect Salah Abdeslam. 

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Brussels' Metro network has partially reopened and soldiers have been carrying out security checks as people enter stations.

Commuters are being asked to show the contents of their bags. 

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Belgium's prime minister Charles Michel has cancelled a scheduled trip to China following the attacks, Reuters reports China's foreign ministry as saying. 

Police have named the brothers they say were the airport suicide bombers as Khalid and Brahim El Bakraoui. 

They say Khalid, under a false name, rented the flat in the Forest borough of the Belgian capital where police killed a gunman in a raid last week, Belgium public broadcaster RTBF said. Investigators, who raided the flat, found an Islamic State flag, an assault rifle, detonators and a fingerprint of Paris attacks suspect Salah Abdeslam, who was arrested three days later. 

Both brothers have criminal records, but have not been linked by the police to terrorism until now, RTBF said. 

Image source, AP

The airport suicide bombers were brothers who were known to police, Reuters quotes Belgian public broadcaster RTBF as saying.

The death toll overnight has stayed at 34, although officials haven't been specific about how many people died at either location. At least 20 were killed at the Maelbeek metro station and about 11 at the airport, officials have said. Scores of others were injured.

To recap: Belgian police are still searching for a suspect spotted on CCTV at Zaventem airport just before the explosions there. It is thought that two men seen alongside him blew themselves up but his explosives failed to detonate.

Welcome back to our live coverage of events following Tuesday's bomb attacks in Brussels. We'll have the latest updates throughout the day.