Leyonhjelm says terrorists are 'very dangerous d---heads' on Q&A

Terrorists are "very dangerous d---heads", according to Liberal Democrats senator David Leyonhjelm.

Appearing on Q&A last night, the senator rejected claims made by Social Services Minister Christian Porter that the Paris and London terrorists were "sophisticated".

"Most of them get caught before they do anything damaging," he said.

"Compare that to drug smugglers most of whom don't get caught."

Leyonhjelm also rejected suggestions of cracking down on social media to stop the proliferation of terrorism.

"It's nonsense, it's like blaming the telephone for a bunch of bank robbers conspiring to rob a bank."

Porter said 12 terror attacks had been prevented since 2014, resulting in the arrest of 63 people.

"These terrible criminal deeds are perpetrated by highly organised, sophisticated groups," he said.

"Our intelligence agencies are dealing with a high level of sophistication, both in the radicalisation of the offences, but also in the way they play out on the ground."

The comments came hours after a Somalian-born man was shot dead after opening fire on officers during a hostage situation in the Melbourne suburb of Brighton.

Yacqub Khayre had faced court in the past over a plot to attack the Holsworthy Barracks in Sydney eight years ago.

Khayre was on parole for a violent home invasion for which he served jail time, according to reports.

He had murdered another man in the foyer of a block of serviced apartments yesterday afternoon and was holding another woman at gunpoint.

Both the murdered man and the woman held hostage worked at the apartment block.

Islamic State has claimed responsibility for the terrorism attack.