A poisonous gas leak at a Tip Top factory in Auckland was the source of a loud siren heard by many residents tonight.
An ammonia alarm sounded about 9pm at the Mt Wellington icecream factory and was heard throughout east Auckland, said Fire Service spokesman Paul Radden.
"It was anammonia alarm at Tip Top," he said. "Fire Service attended the incident, shut off the valve and liaised with on-site engineers, ventilated the area and then left.
"We were on site less than an hour."
Police had fielded multiple calls about the siren, that some residents believed to be a Civil Defence siren or Tsunami siren, a Police spokesman said.
