NEW HAVEN, Conn. — Climate change activists stormed the field at the Yale-Harvard football game on Saturday afternoon, disrupting the game at halftime in a protest to call attention to the universities to divest their investments in fossil fuels.

A group of about 70 protesters took to the field just before 2 p.m. after the game’s halftime show. They were then joined by others from the stands.

At its peak, the demonstration drew up to 500 people, packing about 45 yards of play between the large numbers that marked yardage, and delaying the game for roughly an hour.

Players from both schools warmed up as police and security officers surrounded the demonstrators and announcements were made on the public address system imploring protesters to clear the field.