said a witness Material people were screaming and being stabbed accidentally.
St John’s ambulance service said five people were injured and four were taken to Auckland Hospital.
However, police later confirmed that four people were injured and suffered “moderate” injuries.
One person was taken into custody by the police.
Curator Naila Hassan praised members of the public for their intervention, saying the incident could have been much worse.
It appeared to be a random attack, with no evidence of hate crime.
Hassan said less than 10 minutes had passed between the police alert and the suspect’s arrest.
Issac Hong, an employee at CafeBayBay in Murrays Bay, said Material there was a woman stabbed at the bus stop opposite his cafe.
Hong said the alleged stabber then ran to Murrays Bay Beach and attacked an “elderly Asian couple”.
Hong said he was told by witnesses in the area that the alleged knife ran into Mairangi Bay and was chased by construction workers from a nearby construction site.
According to Hong, police managed to arrest the alleged perpetrator in Mairangi Bay.
A lady on her morning walk with a dog said the builder used his crutches to stop the alleged stabber.
He saw a hooded man coming out of Seaton Road and started stabbing people.
The man chased a 17-year-old girl who screamed, he said.
“We thought she was stupid, she was screaming,” he said.
“He stabbed two people, completely by accident … everything happened very quickly.”
She was only 20 meters away from the man at some point.
“He then tried to stab another teenager, but she escaped,” he said.
Police said they were still working to confirm the number of injured.
“People are screaming. Everything is happening so fast. People are running, and the police were there at the same time with big guns, and they have someone on the floor at that moment,” said local Maria Paz Tapia.
Another Mairangi Bay resident said he saw “several police officers” in the area.
“I saw three or four passing by here to Murrays Bay and an ambulance as well,” he said.
Police have made detours around the incident and are urging people to avoid the area.
Mothers who were on the beach with their children for a game appointment around 10.30 am. they said a lady came and told them to take their children and run.
Shortly afterwards, another man ran up to them and shouted the same thing.
“At first I thought it was a tsunami or something like that because we’re on the beach,” said Dianne Hilbourne.
She had her three-year-old son with her.
“We just left everything and ran.”
Alexandra Bate was also on the play team with her five-year-old daughter and one-year-old son.
“We just ran. Straight to the houses where we knew we would be safe. We did not know what was going on,” he said.
Mom’s team and their children came out safe when they saw the police arriving.
Hilbourne said she saw a man fall to the ground in the parking lot.
“I think he was one of the victims, I could not understand,” he said.
“A day went by, we thought it was just a day at the beach, you know?”
Local councilor Chris Darby said “his heart aches for the victims’ family and friends and for what they are going through.”
“I can assure the community that there is no harm to anyone else, the police arrested the perpetrator with the help of brave locals,” Darby said, referring to the construction workers who intervened.
“It’s extremely brave to put themselves in danger as they did.”
East Coast Bays MP Erica Standford said Murrays Bay was a small community that would feel the impact of the attack.
“I am sure that the police arrested the person concerned,” he said.
National Police spokesman and MP Mark Mitchell said what happened near a normally quiet beach was “tragic”.