Prime Minister Malcolm Turnbull says Europe allowed its terrorism preparedness to "slip" before the bombings in Brussels, Belgium that killed at least 34 people and left more than 200 more people recovering from various injuries.  The opposition says it's too soon to "hand out advice".

The so-called Islamic State claimed responsibility for the twin bombings at Brussels' airport and at the Maelbeek subway station which is in the heart of the Belgian capital near several European Union buildings.  One suspect who for whatever reason didn't blow himself up at the airport is on the run.

Speaking to the ABC, PM Turnbull expressed Australia's "most resolute solidarity" with the Belgian people.  But he also criticized Europe's border protection and the free movement "Schengen Zone" which allows people and goods to travel from country to country without border checks. 

"There's been a real breakdown in intelligence," said PM Turnbull.  "If you can't control your borders, you don't know who's 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," he added.

Opposition leader Bill Shorten says now is not the time for an Australian Prime Minister to be "telling the Belgians what they did wrong".

"For me, today, is about recognizing that people have lost their lives - innocent people have lost their lives," said Mr. Shorten.  "No doubt the hard questions will be asked in coming days."