Police on alert for threatened terrorist attack

5.00pm - by IAN STUART

Police are on increased alert in Auckland and Wellington as the second key date approaches for threatened attacks in the two cities.

If the second threat materialises as promised in a letter to the New Zealand Herald newspaper earlier this month, it will happen at midday tomorrow.

The first threat, to release cyanide into water supplies and cyanide gas into cinemas if and when Iraq was invaded, failed to materialise when the war began last week.

Now authorities are waiting to see if the second threat of a "demonstration of capabilities" happens at the stated time of noon tomorrow.

The "demonstration of capability" could include dumping cyanide into water supplies in houses and motels, and releasing cyanide gas into cinemas, the letter said.

Iraq was invaded last week but no poison was released as promised.

"Step one didn't happen but we don't know about step two (the demonstration)," police national headquarters spokesman Jon Neilson said.

The Herald letter followed four other letters to embassies and high commissions. Two contained cyanide powder.

In one of the letters the writer claimed to have 25kg of "weapons-grade" cyanide, a term unlikely to be used by someone with knowledge of cyanide.

"There is no such thing as weapons-grade cyanide," he said.

The letters sparked a security increase at cinemas, hotels and motels and at water reservoirs in both Wellington and Auckland.

Scientists believe that, with a little knowledge, it would not be difficult to carry out the threat to contaminate motel and hotel water supplies.

Poisoning could be carried out on the internal supply of a specifically targeted establishment, but not the main water supply feeding it, a scientist, who did not want to be named, told NZPA.

Watercare Services spokesman Owen Gill refused to discuss security at the numerous water reservoirs around Auckland which supply the city with water.

"We are satisfied the security arrangements that are in place are adequate to meet this type of threat."

He would not confirm locks had been changed and security cameras installed at some reservoirs.

"The security is good," Mr Gill said.

"The probability of being able to infect a water supply in a way that it would materially affect the population of Auckland is low," Mr Gill said.

The quantity of cyanide needed would be far more than anyone was likely to have, Mr Gill said.

The scientific community believes that while releasing gas into cinemas would be relatively easy, the gas would need to be stored under pressure in a gas bottle similar to a barbecue bottle and that would be difficult.

Filling a bottle with cyanide gas could be extremely dangerous to the operator, the scientist said.

Police said that while the letters were being treated seriously, they believed the threat to the country was low.

They also urged the public not to panic but to report suspicious activity around hotels, motels and cinemas.

Cinema staff were told to look for suspicious bags and packages, keep aisles and exits clear, check evacuation procedures, remove rubbish and items left between screenings, and check security on ventilation systems.

Hotel and motel staff have also been told to be vigilant for suspicious activity.

Mr Neilson said today there was an increased level of awareness but not a huge increase in police activity.

He said police still did not know who had written the letters, including those which contained cyanide.

- NZPA