A leader of Dunedin’s Muslim community is thankful for the support, but is concerned some online activists are taking it too far, including by naming alleged attackers.
The petition has gathered more than 50,000 signatures online and is calling for the school to act after a video emerged of the alleged attack.
American model Bella Hadid, who is of Palestinian and Dutch descent, posted a message of support to her Instagram account, which has 49 million followers.
She said the incident brought tears to her eyes and made her "angry and sick to my stomach".
"I am so sorry to the ones that have felt this kind of disrespect."
New Zealand figures also put forward messages of support.
Former All Black Sonny Bill Williams posted a video to his Instagram page sending out support to the girls involved.
"These thugs may rip your headscarves off your head, but they’ll never rip Islam or Allah from your hearts."
He hoped the attackers were met with "the full force of the law".
"Such behaviour has no place in NZ".
One of the victims was Hoda Al Jamaa (17), who spoke to RNZ earlier this week.
She said she was filmed while beaten and had her hijab forcibly removed by pupils of the school.
She was taken to hospital after the attack.
Otago Muslim Association chairman Dr Mohammed Rizwan said it was important to give the school and police time to complete their investigation.
The association was working with the school and police on the incident.
He appreciated the widespread support and it could help ensure similar events never took place again, but he was concerned some were taking it too far.
This included those publicly naming and shaming the alleged offenders, Dr Rizwan said.
The offenders needed to face "severe consequences" but doing anything that could jeopardise their safety, or the processes being worked through, was out of line.
The most important thing was the victims felt justice had been upheld.
However until then the school needed to be given the opportunity to work through the issue, Dr Rizwan said.
"It is not the time to play the blame game."
The association announced on Wednesday evening a high-level review meeting between the Federation of Islamic Associations of New Zealand, the Islamic Women’s Council of New Zealand and the Ministry of Education had been urgently convened.
A letter from school board of trustees chairwoman Lyn Hurring was sent out to parents yesterday.
The board had completed its formal disciplinary process, she said.
The legislation put the responsibility in the hands of the board, not the principal.
It could not share the outcomes of the process, but it was "confident that strong and appropriate steps were taken".
Meanwhile, Dunedin North Intermediate principal Heidi Hayward said accusations online of Islamophobic bullying involving its pupils were "absolutely incorrect".
The person who reported the event "made an assumption" and evidence showed the incident was caused by misuse of social media, she said.
