Aussie PM slams "cowardly" terror attacks in Brussels

Australian Prime Minister Malcolm Turnbull on Wednesday slammed the "cowardly" terror attacks which rocked the Belgian capital city of Brussels.

The Australian prime minister also said the European Union (EU) let its security "slip" in the lead up to the bombings.

Turnbull offered the "most resolute solidarity" to the people of Belgium in the wake of the coordinated attacks claimed by the Islamic State (IS) and admitted Europeans were more at risk than other nations because of the EU's lackadaisical security measures in the wake of the Syrian refugee crisis.

"Australians condemn these cowardly attacks in Brussels and the people of Belgium have our thoughts and our prayers are with them but, above all, our most resolute solidarity," Turnbull told the Nine Network on Wednesday morning.

"We are utterly united, completely united in the fight against terrorism, in the fight against this sort of cowardly violence."

The blasts, which occurred at the Belgian capital's airport and at the Maalbeek railway station, have killed more than 34 people and injured hundreds.

Speaking to Australian Broadcasting Corporation (ABC) television later in the morning, Turnbull said the European nations had "allowed their security measures to slip" in the wake of the Syrian refugee crisis, in which millions of refugees were allowed into European nations without background checks.

He said the attacks would prove to be a "lesson for us all", adding that he had no doubt the "very porous" borders would be more strictly controlled in the future.

"There's been a real breakdown in intelligence. If you can't control your borders, you don't know who is coming or going. Regrettably they allowed things to slip and that weakness in European security is not unrelated to the problems they've been having in recent times," Turnbull said.

"Europe has, for all intents and purposes, internal borders, so people can travel within Europe as they wish, and their external borders have been very porous as we've been seeing every night on the news."

The prime minister said Australia's Department of Foreign Affairs and Trade (DFAT) had upgraded its travel warnings for Belgium but added he could not guarantee Australia was safe.

"We can't guarantee that there will not be a terrorist incident in Australia. That's why the threat level is set at 'probable'. But we are in a much stronger position than our friends in Europe are," Turnbull told the Seven Network.

"It's a sad state of affairs in Europe. They have allowed their security measures to slip and this is a lesson to all of us, to absolutely keep your guard up at all times."

Meanwhile, Foreign Minister Julie Bishop said DFAT was working hard to determine whether any Australians were caught up in the attacks. She said the Australian embassy in Belgium was just two kilometers from one of the blasts.

"Our thoughts and sympathies are with the people of Belgium," Bishop said in a statement.

"The Department of Foreign Affairs and Trade is urgently seeking to determine whether any Australians have been affected."

The attacks follow a series of coordinated terror attacks, also claimed by IS, which rocked the French capital of Paris in November last year, in which attackers killed 130 people. Endit