Netsafe is issuing warnings to schools and parents after a disturbing video was shared on social media.
The video deals with suicide.
A TikTok spokesperson said on Sunday night US time, the clips were livestreamed on Facebook and circulated on other platforms, including TikTok.
"Our systems have been automatically detecting and flagging these clips for violating our policies against content that displays, praises, glorifies, or promotes suicide," the spokesperson said.
"We are banning accounts that repeatedly try to upload clips, and we appreciate our community members who've reported content and warned others against watching, engaging, or sharing such videos on any platform out of respect for the person and their family.
"If anyone in our community is struggling with thoughts of suicide or concerned about someone who is, we encourage them to seek support, and we provide access to hotlines directly from our app and in our safety centre."
Netsafe chief executive Martin Cocker said his staff were working directly with social media companies.
"Netsafe has very good relationships with the main social media platforms," he said.
"As New Zealanders report in disturbing content they find, we then work with those platforms to have it recognised and removed."
His organisation had received seven reports about it since it came to staff's attention yesterday.
Netsafe was sending out information to schools that were concerned.
Mental Health Foundation chief executive Shaun Robertson said the video could cause distress.
"As it may have been widely viewed, the foundation has decided to speak out requesting parents, caregivers and others supporting young people take proactive steps to check in on young people and anyone who may be at risk of suicide.
"It's up to us to bridge the gaps between adults and rangatahi and ensure we're there to help," Robinson said.
"Social media can be a huge positive for many young people - banning it isn't the answer. We need to ensure young people feel they can safely talk to the adults in their lives about distressing things they have seen or heard without fear of punishment or losing access to social media."
Chief Censor David Shanks said parents should be wary of what their children were watching.
"This is a good opportunity now for parents to check in with their children about things that they may have seen, not just video, but to connect with them about things they may have seen or may have even heard people talking about that could be disturbing or upsetting for them."
Netsafe's advice on dealing with upsetting content can be found here.
Where to get help:
Need to Talk? Free call or text 1737 any time to speak to a trained counsellor, for any reason.
Lifeline: 0800 543 354 or text HELP to 4357
Suicide Crisis Helpline: 0508 828 865 / 0508 TAUTOKO (24/7). This is a service for people who may be thinking about suicide, or those who are concerned about family or friends.
Depression Helpline: 0800 111 757 (24/7) or text 4202
Samaritans: 0800 726 666 (24/7)
Youthline: 0800 376 633 (24/7) or free text 234 (8am-12am), or email email@example.com
What's Up: online chat (3pm-10pm) or 0800 WHATSUP / 0800 9428 787 helpline (12pm-10pm weekdays, 3pm-11pm weekends)
Kidsline (ages 5-18): 0800 543 754 (24/7)
Rural Support Trust Helpline: 0800 787 254
Healthline: 0800 611 116
Rainbow Youth: (09) 376 4155
If it is an emergency and you feel like you or someone else is at risk, call 111.