Although the Government continues to rate the domestic risk here as low, meaning an attack is considered possible but not likely, Prime Minister John Key has disclosed that one or two individuals among about 40 on a terrorist watchlist are deemed so threatening they are being monitored every minute of the day.
"It only takes one person to do something crazy," he said.
Auckland-based intelligence expert Dr Paul Buchanan, a former terrorist profiler for the CIA, described the US alert as an acknowledgment of the global reach of Isis through social media and said transport hubs such as Britomart could not be ruled out as prime targets.
Asked whether even Auckland's Farmers Santa Parade on Sunday or the memorial
to All Black great Jonah Lomu at Eden Park on Monday could be at risk, Dr Buchanan said: "We have to trust the security authorities, the police, to do their normal contingency planning but this [the terrorism threat] is an added concern."
He said Auckland Transport needed to review its security protocols, including for the Kingsland railway station near Eden Park "and of course any parade". Individuals needed to practise better situational awareness when in public places.
"That goes right in the ear and out the other for most Kiwis because we are far away and people would say no one's going to come down and hurt us during my morning commute.
"But we are involved in the fight against Da'ish [Isis], we've got troops on the ground - our intelligence services are obviously completely tied into the western networks trying to fight them and the bad guys know that."
AT operations centre manager John Strawbridge said it would "for obvious reasons" not comment on the details of security at any of its facilities, except to note it had CCTV coverage under 24-hour monitoring across its networks.
An Auckland Airport spokesman said his company held regular discussions with the police and other government agencies about security but it was not appropriate to disclose details.
Waikato University law professor Alexander Gillespie said the number of terror attacks in the US had declined under tighter security and surveillance, meaning Americans tended to be at more risk when travelling overseas.
He appealed for the public not to overreact.
"People have a much greater risk of dying of domestic violence in this country than we have of a terror incident ... "
Kiwi travellers get more security-conscious
New Zealand embassies in France and Belgium have reported an increase in Kiwis registering their presence there since the terror attacks on Paris 11 days ago.
But that is believed to be because they have become more security conscious after 130 people died in the attacks, rather than as a result of any influx of New Zealand visitors.
The Minister of Foreign Affairs and Trade said yesterday that 411 Kiwis were registered on its SafeTravel service as being in France, and 68 in Belgium, where our embassy will remain closed today during a security clampdown in Brussels.
The Flight Centre travel agency says "a handful" of its customers have chosen to reroute trips to the Northern Hemisphere through other parts of Europe.
But its NZ general manager, Sue Matson, said many others approaching the agency with inquiries since the Paris attacks had simply wanted to talk through their options and she did not foresee any major effect on bookings.
"New Zealanders are [generally] quite resilient and tragically, terrorism is a part of life around the world now," she said.
Travellers might be more vigilant but they'd still travel.
Additional reporting: Isaac Davison, Solbin Kang