Students at the University of Missouri have been demonstrating for weeks for the ouster of the university president, protesting the school’s handling of racial tensions. But their movement received a boost over the weekend when dozens of black football players issued a blunt ultimatum: Resign or they won’t play.

Fueling the anger were a series of on-campus incidents: racial slurs hurled at black students and feces smeared into the shape of a swastika on a wall in a residence hall. What many students viewed as a sluggish response from the administration gave rise to calls for the removal of the president, Timothy M. Wolfe.

The Legion of Black Collegians, which administers campus groups that primarily serve black students, posted a photograph to Twitter on Saturday night of more than 30 football players linked in arms with a graduate student who is staging a hunger strike.

“The athletes of color on the University of Missouri football team truly believe ‘injustice anywhere is a threat to justice everywhere,’” a message accompanying the photo said, quoting a line from Martin Luther King Jr.

The protesting players received the backing of their coaches and many of their white teammates, and on Sunday evening two groups representing graduate students and graduate student workers said they would stage walkouts on Monday and Tuesday in solidarity with the activists and in protest of Wolfe’s response.

The Board of Curators, the nine-member governing body of the University of Missouri, said it would hold a closed-door meeting on Monday morning.

The strike reflected a growing willingness among black college students at predominantly white institutions to demand quick action and stronger responses from officials to reports of racial antagonism. Their efforts dovetail with broader pushes against inequality and injustice like the Black Lives Matter movement, which arose in response to a string of fatal police shootings of unarmed black civilians, including the death of Michael Brown last year in Ferguson, Missouri.

Officials in Missouri were grappling with how to respond to the boycott, which could cost the university more than $1 million if the team forfeits a game scheduled for Saturday. On Sunday, the protesting players received the backing of their coaches and many of their teammates.

Wolfe said in a statement on Sunday that his administration was working to address the students’ concerns, including a list of demands from a campus activist group spearheading the demonstrations, and promised to share the next steps as soon as they were confirmed.

“My administration has been meeting around the clock and has been doing a tremendous amount of reflection on how to address these complex matters,” he said. “We want to find the best way to get everyone around the table and create the safe space for a meaningful conversation that promotes change.”

His response did not quell frustration among demonstrators, both black and white, who were camped out in tents on the Mel Carnahan Quadrangle at the center of the campus. Storm Ervin, a senior, said Wolfe’s refusal to resign showed that he was out of touch.

“We’ve had departments supporting us. We’ve had faculty supporting us,” she said. “People who he leads are standing in solidarity with us.”

Ervin pointed out the university chancellor, R. Bowen Loftin, who brought food to the campsite and spoke with students Sunday afternoon. Loftin was an early target of the demonstrations before criticism shifted to Wolfe.

A prolonged strike could have costly consequences for the players, some of whom depend on athletic scholarships, and the university, which draws revenue from ticket sales and the sale of television distribution rights. If Missouri forfeits Saturday’s game against Brigham Young University, it would be required

to pay $1 million to BYU, according to a copy of the contract between the two schools published by The Kansas City Star in January.

(END OPTIONAL TRIM.)

Sixty of the 124 players on the Missouri football roster are black, although it is not clear whether all of them are participating in the strike, according to The Columbia Missourian, a newspaper published by faculty and students.

The players’ boycott follows a decision by a black graduate student, Jonathan Butler, to go on a hunger strike over what he said in a letter to the board of curators were “a slew of racist, sexist, homophobic, etc., incidents that have dynamically disrupted the learning experience” of minority groups at Missouri.

Some people on social media applauded the players for taking a stand, and the players received support from the athletics department as well as the coaching staff, their teammates and some public officials in Missouri. After a meeting with the football team on Sunday at the school’s athletic training complex, coach Gary Pinkel declared his support for the demonstrating players with a team photo on Twitter.

In a joint statement with Mack B. Rhoades IV, the athletics director, Pinkel said practices and team activities scheduled on Sunday had been canceled to focus on resolving the impasse.

Missouri’s attorney general, Chris Koster, urged the university to set up a task force to address the students’ concerns. Claire McCaskill, the senior U.S. senator from Missouri and an alumna of the Columbia campus, said the board of curators needed to “send a clear message” to the students that they would address racism. Gov. Jay Nixon also issued a statement urging officials to address the students’ concerns “to ensure the University of Missouri is a place where all students can pursue their dreams in an environment of respect, tolerance and inclusion.”

But the players also saw backlash, including some calls for scholarships to be revoked for players participating in the protest.

The campus was set on edge after Brown, an unarmed black teenager, was fatally shot during a scuffle with a police officer in Ferguson, about 110 miles from Columbia. About 8 percent of the 27,654 undergraduates on campus were black in 2014, according to enrollment figures. And a number of the black students come from Ferguson, where about two-thirds of the population is black, to Columbia, where nearly 80 percent of residents are white.

Frustrations have mounted since September when Payton Head, the president of the Missouri Students Association, who is black, said a man had called him a racial slur as he walked on campus. Students protested for a week before Loftin, the chancellor, responded to the incident.

In October, members of the Legion of Black Collegians reported that someone had yelled a racial slur as they rehearsed for a play in a campus plaza. Later that month, someone used feces to draw a swastika in a bathroom inside a new dormitory. At the homecoming parade last month, students formed a human chain to block Wolfe’s car in an attempt to speak with him after officials did not respond to earlier requests to talk to him, the students said. Wolfe, who did not get out of the car, later apologized for his reaction.

The tensions prompted a group of 11 student activists to form Concerned Student 1950, named for the year the university began admitting black students.

Wolfe took office in 2012 and oversees the system’s four campuses in Columbia, Kansas City, St. Louis and Rolla. Missouri’s board of curators voted last year to extend his contract. A board document showed that the contract, scheduled to expire in 2018, included a base salary of more than $450,000, as well as potential performance bonuses.

In response to the demonstrations, he has met with Butler and the leaders of the Concerned Student 1950. In a statement on Thursday, Wolfe expressed concern for the graduate student’s health and said racism at the school was “unacceptable.”

On campus on Sunday, many Missouri football players declined to comment on the boycott. But Jason Reese, a tight end, said the players would end their strike “after all this gets resolved.”

“I feel great,” he said. “And I love my teammates.”