A Taranaki high school has reopened after being on lockdown for almost three hours when a gunman was reported on the grounds.
Police lifted the cordon about 11.30am and staff were speaking to students.
A police spokeswoman said officers were working to establish whether or not there had been a gunman in the first place.
However, no one fitting the description had been found. No firearm had been found either, she said.
A 17-year-old student described the harrowing scenes as he arrived at school.
"As I'm walking down towards the classrooms, there's these bells just going off. My first reaction was that the school timetable has changed and it's time to go to class now.
"But then as I look around, I see everyone running. I hear yelling everywhere. I look into one of the windows and my friend is sitting there - and he's telling me to hurry up and get inside.
"I run inside and he just screams at me that there's a lockdown happening.''
The student said he ran back outside to get someone unaware of the seriousness of the situation and brought them back into the classroom.
The teacher then locked the door and stapled bits of paper on the windowpanes, to cover them. They quickly shut the curtains and spent the next three hours sitting in almost silence.
Sergeant Andrew Russ said a person with a firearm was also reported near the school on Tuesday.
"There was possibly a call earlier in the week, similar sort of details were given," he said.
Russ said that call was anonymous and police were looking into whether the two reports were linked.
Large numbers of police from as far afield as Hawera and New Plymouth went to the school just before 8.30am after a man with a gun was reportedly seen on the grounds.
"It's not something we deal with in Stratford much," Russ said.
Students arriving at school were turned away, although some were in their classrooms, as officers set up a cordon and school buses diverted to a park down the road.
A kindergarten next to the secondary school was also put on lockdown.
One frightened 15-year-old girl texted her mother from inside a locked classroom to say someone had been trying the door handle.
The school Facebook page posted a message asking families not to panic, advising all students were safe and police had the situation under control.
About 10.30am, the school posted another update telling parents that some buses were stopped at Victoria Park - just down the road from school grounds.
Students on buses East Rd/Toko, Eltham Dairy bus and the Eltham Library bus had all been diverted to the park.
"If your [children] were on any of these buses, you can go and collect them from there. If you are unable to collect them, they will be supervised there until the lockdown is over and then brought back to school.''
Police dogs and handlers have been combing the area, as well as armed officers.
Witnesses say they heard a man was seen walking through the Taranaki school with a gun.
Some students arriving by bus were taken to a nearby park with some teachers while others remained in classrooms and the school hall.
Clusters of worried parents gathered around the police cordon.
Shortly before 10.30am police began moving people further back from the cordons.
Some parents had contacted their children by text and were trying to reassure them.
Police were reiterating to parents there had been no reports of shots fired and all students were believed to be safe.