Australia says Europe let security `slip`

Sydney: Australian Prime Minister Malcolm Turnbull on Wednesday said Europe had "allowed security to slip", as he questioned the EU`s Schengen passport-free zone in the wake of the Brussels attacks.

Turnbull`s comments came as Belgium`s neighbours France, Germany and the Netherlands tightened border security after some 35 people were killed in Belgium`s worst extremist assault.

The Australian leader said while it was up to Europe to set its policies, his nation`s border protection measures and domestic security arrangements "are much stronger than they are in Europe where regrettably they allowed security to slip".

"That weakness in European security is not unrelated to the problems they`ve been having in recent times," he told the Australian Broadcasting Corporation, alluding to the wave of migrants who have flooded into the continent, many of them from Syria.

Turnbull added that the open-borders Schengen travel regime, which covers 26 of the 28 EU countries, meant "people are able to freely travel across borders within Europe -- that poses security challenges, coupled with clearly very porous external borders as we`ve seen plenty of evidence of that".

"My point really was to say that those arrangements have security consequences," he told reporters in Sydney.