Armed officers closed off Riverbend Rd between Morris Spence Ave and Arnold St about 9.30am while armed offenders squad officers went into the area around Henry Charles Cres.
As a precaution William Colenso College students were kept within the grounds.
It was not yet known what the incident involved although it is understood a threat had been made and the person involved may have indicated they had a firearm.
A police representative said the parties involved were known to each other.
One resident nearby said the police arrived "silently" and without a fuss.
He had seen armed officers walking into the closed off area looking in properties.
Police were also checking boots of vehicles of residents who live within the closed off zone and were driving out.
A status posted on the school's facebook page earlier this morning stated they were currently in lockdown.
"We are currently in a lockdown situation, we are working closely with the police," it read.
"All students and staff are safely locked in at school. Please do not come into school until further notice. We will keep you informed. Further information can be found at the Eastern District Police Facebook site."
The college had been in lockdown since 9am following police instructions, said principal Daniel Murfitt.
The college went straight into lockdown procedure, with teachers locking their classrooms and advising students to stay away from the windows.
"They key for us is communicating with home so that's why it's on Facebook to let parents know it's under control here."
Murfitt said he was confident police had the situation under control and now students were at school he felt more sure they were safe.
"Clearly at the beginning we were concerned for students coming to school and on their way to school. Now it's fully into the school day we're less concerned ."
