The National Radio reported Sunday that police have upgraded security at stations, including hiring security guards to patrol the Wellington central station.

Cops have urged the public to be aware of suspicious characters hanging around cinemas, motels and hotels. Movie theatres have employed security guards to check patrons' bags.

The move follows threats to release cyanide gas into cinemas and poison water supplies.

The threats were made by a group calling itself September 11 last month.

In letters to a newspaper and the American and British embassies, it said the group had 25 kg of "weapons-grade cyanide".

The writer of the letter threatened to demonstrate the group's terror capability by strikes on March 28, at noon, in Auckland and Wellington.

(Xinhua News Agency March 23, 2003)