An 'act of war'

People gather in the Octagon in Dunedin yesterday to remember the victims of the terror attacks in Paris on Friday. Photo by Gerard O'Brien.

Suspected terrorists behind one of the worst attacks on French soil since World War 2 have been rounded up by police.

Stories have emerged of dramatic actions which may have prevented the death toll from rising even higher.

Arrests were made at the French border yesterday and in Brussels, Belgium, as Islamic State (IS) claimed responsibility for the deadly, co-ordinated attacks across Paris on Friday night.

In all, 129 people were killed. The death toll is expected to rise because 99 of the 352 injured are in a critical condition.

French President Francois Hollande described the attacks as an ''act of war''.

The British Government deployed special forces troops to monitor transport stations, shopping centres and key public places amid fears the UK could be the next Islamic State target, as counter-terrorism sources revealed up to 450 radicalised Britons have returned to Britain from Syria.

Prime Minister John Key, who is in Vietnam for bilateral talks, confirmed no New Zealanders were hurt or killed in the attacks.

At least 300 New Zealand travellers were registered as being in the city at the time.

The Ministry of Foreign Affairs is advising New Zealanders not to travel to Paris unless on urgent business. In New Zealand, the domestic terror threat level remained unchanged at ''low''.

Mr Key said New Zealand's watch list was still about 40.

''I think every country in the world is potentially vulnerable. We are probably less vulnerable than most others.''

New Zealand had the advantage of distance.

'Pools of blood filled the floor'

A woman who survived the massacre inside the Bataclan theatre described playing dead for up to an hour as the gunmen circled ''like vultures'' shooting anyone who moved.

In a harrowing Facebook post accompanied by an image of her blood-smeared shirt, 22-year-old Isobel Bowdery described how she held her breath and thought about loved ones as she lay among the dead and dying.

''Dozens of people were shot right in front of me. Pools of blood filled the floor. Cries of grown men who held their girlfriends' dead bodies pierced the small music venue.

''Shocked and alone, I pretended to be dead for over an hour, lying among people who could see their loved ones motionless.''

Video footage taken by a Le Monde journalist near the theatre showed concert-goers fleeing from emergency exits, some dragging wounded people.

Others climbed out windows as gunshots rang out. A pregnant woman hung from a window ledge by her fingertips, calling for help.

Arrests in Belgium

French police said seven attackers, one as young as 15, worked in three teams across the city and carried out co-ordinated attacks. Several suspects were arrested in Belgium after a car seen near the Bataclan theatre was intercepted crossing the border.

Police then launched raids in the Molenbeek area of Brussels, a neighbourhood known for jihadi activity, and several more were arrested.

IS claimed responsibility for the attacks and warned more would follow.

It said France was singled out for insulting the Prophet Muhammad and for its bombing campaigns against IS in Iraq and Syria.

Two of the suicide bombers were thought to have sneaked into France by posing as asylum seekers, raising concerns about French intelligence and the influx of migrants across Europe's border.

New Zealand is taking 600 additional Syrian refugees and ministers said that would not change.

Acting Foreign Minister Chris Finlayson said the vetting of these refugees was strict and the Government had the power to reject anyone if it believed they posed a security risk.

Mr Finlayson said he hoped New Zealanders would show the same welcome to the Syrian group as it had to Polish and Vietnamese refugees. But he feared an international backlash following the Paris attacks.

One of the gunmen who opened fire at the Bataclan theatre was a French national.

Omar Ismail Mostefai (29) was identified by his severed finger, which was found among the rubble after he blew himself up. He was known to police as a petty criminal.

His father and brother were in custody yesterday and their homes searched.

Global ambitions

Otago University international relations expert Robert Patman told TV3's Paul Henry programme he was "not totally surprised'' the attacks had taken place.

Isis had been clear that it was extending its operations and targeting countries like France since last year, he said.

"This is an organisation with global ambitions,'' Mr Patman said.

"It basically has declared war. It declares war on non-believers and either kills them or enslaves them. And this is the way it behaves in the territory that it has under its control and it has 6 million people under its control, so we shouldn't have any illusions about that,'' he said.