"All the whanau ran out and he boosted off. Some of the cuzzies and my dad and I chased him down to the Opononi and blocked him in got his keys, gave him a few and called the cops. If the cops let him out you know to do [sic]. Pedos don't live long. Please share this all over Facebook and social media apps."
Police said an incident happened at about 1am on Monday, when a man allegedly parked his vehicle in a driveway, asked for directions and then tried to grab the teenagers and pull them into his vehicle.
A police spokesperson said people should not post information about suspected criminals online.
"We strongly discourage any members of the public from taking matters into their own hands and posting any information online which could be used in a potential police investigation. This includes posting photos or videos claiming to show alleged offenders.
"We appreciate that members of the public often have good intent, however this information could be crucial for any police investigation and could potentially run the risk of jeopardising an investigation, therefore we urge people to refer this information to police so we can deal with any information."
"If anyone has any information about a police matter they are encouraged to contact their local police station or phone Crimestoppers anonymously on 0800 555 111."
A 69-year-old man was in custody yesterday and undergoing a medical assessment.
Police said charges were likely.
Facebook comments under the photographs of the alleged offender were highly abusive and threatening.
Police yesterday thanked the members of the public who responded to the two females' cries for help.
"Police would like to thank the local residents for their part in assisting to locate the offender and preventing the potential for any further offending," Detective Sergeant Greg Johnson said.