(NewsNation) – The “suspected perpetrators”. allegedly sprayed a dangerous chemical during a pro-Palestine demonstration Friday at Columbia University were banned from campus, said a statement from the interim provost.

However, there have been no arrests yet, New York police told NewsNation on Tuesday.

Interim Provost Dennis Mitchell said the NYPD is taking the lead role in investigating “apparently serious crimes, possibly hate crimes.”

After receiving additional information Sunday evening, Mitchell said, the “suspected perpetrators” of the chemical attack identified to the university were immediately banned from campus.

He did not elaborate on what additional information was involved or who the alleged perpetrators were. A Columbia spokesman said the university would not comment beyond the content of Mitchell’s statement.

Nearly two dozen students who spoke to The Columbia Spectatorswhich was the first media outlet to report the story, described a “foul smell” and physical symptoms after Friday’s protest, with some saying the substance used was skunk spray.

Skunk spray, loud the BBC, was invented by the Israeli company Odortec and is supplied to the United States by Mistral Security. It has been used by the Israeli Defense Forces against protesters in the occupied West Bank since 2008. Palestinians who were hit describe the smell as “worse than raw sewage” and a mixture of “excrement, noxious gas and a rotting donkey.” .”

On Saturday, a victim filed a report telling police that other participants in the protest told her that an “unknown substance” had been sprayed into the air, the NYPD said. She smelled an odor, police said in an email, and began to feel nauseous and experienced a “burning feeling in her eyes.”

Five more police reports were filed on Sunday.

Eight students were hospitalized and dozens more sought “urgent medical attention,” according to Columbia Students for Justice in Palestine and the Columbia chapter of Jewish Voice for Peace. both of whom were suspended from campus last yearsaid in a joint statement.

“We continue to urge those with relevant information – including images, videos and clothing – to share it with the Department of Public Safety and the NYPD. We are grateful to the members of our community who have already done so,” Mitchell wrote. “We strongly condemn any threats or acts of violence directed at anyone in our community. The university undertakes to take immediate action with the relevant authorities in such cases.”

Columbia SJP and JVP said they hope Columbia’s investigation into the attack means the government will take steps toward accountability.

“This hateful attack came after Columbia had brutally targeted and suppressed Palestinian student advocacy for months, contributing to a hostile environment that fueled violent attacks like this at a time when violent hate crimes against Palestinian, Arab and Muslim Americans are on the rise are dangerously emboldened,” their statement said. “The administration must repair the damage it has caused.”

Experts have said anti-Muslim, anti-Palestinian and anti-Jewish attacks have risen to record levels since October 7, when Hamas militants killed around 1,200 people and took 250 hostages in Israel. Since then, more than 25,000 Palestinians have been killed in Gaza, with Israeli bombings in the area causing widespread death and destruction and displacing an estimated 85% of Gaza’s 2.3 million people.