During halftime of the annual football game between Harvard and Yale on Saturday, hundreds of students and alumni stormed the field demanding that the elite universities divest completely from fossil fuels and cancel their holdings in Puerto Rican debt.

An estimated 500 students and alumni gathered and at sat down at mid-field, holding signs that condemned Harvard and Yale for being "complicit in climate injustice" and chanting "fossil fuels have got to go!"

The protest delayed the football game, which was being aired live on ESPN, for nearly an hour. Demonstrators who refused to leave the field voluntarily were arrested.

Drew Hammel, a Harvard student, told the New York Times that the goal of the demonstration was to "put increased pressure on sources of power at Yale and Harvard and make them realize that this is a student issue."

The student-led protest quickly garnered national attention, with Rep. Alexandria Ocasio-Cortez (D-N.Y.) and 350.org founder Bill McKibben expressing their support on Twitter.

"Activism disrupts the present to change the future," said the New York Democrat.

"Amazing action," tweeted McKibben. "Harvard-Yale Game is literally peak establishment—and they were forced to think about what their investments are doing to the world. Such thanks for this leadership!"

As The Guardian reported, "both schools have massive endowments invested across the economy, including in fossil fuels. Harvard's is worth $39 billion, Yale's $29 billion. Activists believe that if the universities divest, hundreds of institutions will follow them."

Akio Ho, a Yale student from Australia who participated in Saturday's action, said his "country is on fire right now."

"Unprecedented wildfires are ripping through homes," said Ho. "Climate change and the climate crisis is an extremely urgent problem."