Anti-Israel agitators were caught on video lighting flares outside a Columbia University "occupation," as the president of the prestigious New York institution testified before Congress on antisemitism spikes. 

The New York City Police Department said at least four people were arrested early Thursday morning in connection to the ongoing protest at Columbia University, PIX 11 reported. 

Video shared online also showed demonstrators clad in Palestinian flags and other garb shouting through microphones, "We want justice, you say how," with the response being "stop bombing Gaza now," "stop arming Israel," and "end the occupation now." 

Demonstrators set up what they deemed "the Gaza Solidarity Encampment" on campus the day Columbia University President Dr. Nemat "Minouche" Shafik testified before the House Education and the Workforce Committee in Washington, D.C., about the scourge of antisemitism seen after the Oct. 7 Hamas attacks in southern Israel. 

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At one point, progressive "Squad" member Rep. Ilhan Omar, D-Minn., attempted to argue that there have been no "anti-Jewish protests" on campus, only those that are either "pro-war" or "anti-war." However, House GOP Chair Rep. Elise Stefanik, R-N.Y., challenged Shafik's earlier testimony, getting the university president to concede that, indeed, the campus demonstrations where protesters shouted chants including "F the Jews," "Death to Jews," "F Israel," "No place," "Death to the Zionist state," and "Jews out" were indeed "anti-Jewish." 

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House Republicans also grilled Columbia leadership over tenured professor, Joseph Massad, who celebrated the Oct. 7 attacks and Hamas' slaughter of nearly 1,200 Jews as "awesome," "astonishing," "astounding" and "incredible." Shafik later confirmed Massad is under investigation for the antisemitic remarks, though he maintains his employment at the school. 

Hundreds of protesters swarmed Columbia University's South Lawn while Shafik testified Wednesday, demanding "divestment" from Israel, according to the student newspaper, the Columbia Spectator.

"The presence of tents on South Lawn is a safety concern and a violation of university policies," a university spokesperson wrote in a statement to the Spectator. "We are informing the students they are in violation of university policies and for their own safety and for the operation of the university they need to leave."

The student paper reported that the anti-Israel protesters were given paper notices from the university informing them around 7 p.m. that they should "immediately cease your participation in this encampment and leave the campus." 

The university notice told protesters to "disperse by 11:00 a.m." or "they would face sanctions."

The congressional hearing also featured discussion over consequences for students carrying out antisemitic demonstrations. The school suspended several students over an unsanctioned event that featured a speaker with known ties to a terrorist group, but lawmakers noted at Wednesday's hearing that those same students came back to campus and protested again anyway.