NEW HAVEN, Conn. (AP) — The 136th edition of The Game between Harvard and Yale has been delayed at halftime after protesters took over the field.

Students from both schools occupied midfield after the Yale band had finished performing. Some held banners asking their colleges to act on climate change and Puerto Rican debt relief.

“Hey hey, ho ho, fossil fuels have got to go,” some protesters chanted.

After a few minutes, hundreds more people stream onto the field. A public address announcement asked them to leave “as a courtesy to the players.”

Video of the field storming for the Harvard-Yale protestpic.twitter.com/O6UgvUJRB5 — Yahoo Sports (@YahooSports) November 23, 2019

At halftime of Harvard-Yale a sit in protesting climate issues has broken out on the field, at least delaying the second half and the way the protest is growing I would be shocked if the game continues. pic.twitter.com/2BWCU2fLuI — Joel Sherman (@Joelsherman1) November 23, 2019

Harvard yale game halted by student #climate protests pic.twitter.com/MLmiRZFwLs — Anya Kamenetz (@anya1anya) November 23, 2019

“As a courtesy to both teams, the game must resume.”

Police were on standby.

With Yale hoping to clinch an Ivy League title, Harvard led 15-3 at halftime.