Updated

A faculty group at the University of Missouri called for professors and other staff to walk out of classes Monday and Tuesday in the latest protest against the university president's handling of a series of racially charged incidents.

The protests began after the student government president, who is black, said in September that people in a passing pickup truck shouted racial slurs at him. In early October, members of a black student organization said slurs were hurled at them by an apparently drunken white student. Recently, a swastika drawn in human feces was found in a dormitory bathroom.

More recently, two trucks flying Confederate flags drove past a site where 150 students had gathered to protest on Sunday, a move some saw as an attempt at intimidation. One of the participants, Abigail Hollis, a black undergraduate, said the campus is "unhealthy and unsafe for us."

"The way white students are treated is in stark contrast to the way black students and other marginalized students are treated, and it's time to stop that," Hollis said. "It's 2015."

USA Today reported that The Concerned Faculty urged its members to stage a teach-in at the plaza where dozens of the school's African-American students and their supporters have gathered for the past week.

More than two dozen football players at the school have drawn national attention to the protests by announcing that they would not participate in team activities until University of Missouri System President Tim Wolfe is removed. Head football coach Gary Pinkel and athletic director Mack Rhoades expressed solidarity with the players and showed support for a Missouri student staging a hunger strike

The Concerned Student 1950 group, which draws its name from the year the university accepted its first black student, has demanded, among other things, that Wolfe "acknowledge his white male privilege," that he be removed immediately, and that the school adopt a mandatory racial-awareness program and hire more black faculty and staff.

Wolfe hasn't indicated he has any intention of stepping down, but agreed in a statement Sunday that "change is needed" and said the university is working to draw up a plan by April to promote diversity and tolerance. He said that most of the group's demands have already been incorporated into the university's draft plan for promoting tolerance.

Already, at Chancellor R. Bowen Loftin's request, the university announced plans to require diversity training for all new students starting in January, along with faculty and staff.

The Columbia Daily Tribune reported that Wolfe was confronted outside a fundraising event in Kansas City Friday night by protesters who asked him to define systemic oppression. According to video of the encounter posted on Twitter, Wolfe responded that the students may not like his answer before saying, "Systematic oppression is because you don’t believe that you have the equal opportunity for success —"

That statement provoked anger from the protesters, one of whom asked "Did you just blame us for systematic oppression, Tim Wolfe?" as the president walked away.

But the actions of the football players have garnered the most media coverage.

"The athletes of color on the University of Missouri football team truly believe 'Injustice Anywhere is a threat to Justice Everywhere,'" the players said in a statement. "We will no longer participate in any football related activities until President Tim Wolfe resigns or is removed due to his negligence toward marginalized students' experience. WE ARE UNITED!!!!!"

It was not immediately clear what the football players' statement would mean for the university's next game Saturday against Brigham Young University. The game is scheduled to be played at Arrowhead Stadium in Kansas City, and canceling it could cost the school more than $1 million.

Pinkel expressed solidarity on Twitter,posting a picture of the team and coaches locking arms.

Practice and other team activities were canceled Sunday, Pinkel and Rhoades said in a joint statement. The statement linked the return of the protesting football players to the end of the hunger strike by Jonathan Butler, who began the effort Nov. 2 and vowed to not eat until Wolfe was gone.

"Our focus right now is on the health of Jonathan Butler, the concerns of our student-athletes and working with our community to address this serious issue," the statement said.

Democratic Gov. Jay Nixon said the university must address the concerns so that the school is "a place where all students can pursue their dreams in an environment of respect, tolerance and inclusion."

U.S. Sen. Claire McCaskill, a Missouri graduate, said the governing board needs to "send a clear message" to the students at the Columbia campus that they'll address racism.

The racial issues are just the latest controversy at the university in recent months, following the suspension of graduate students' health care subsidies and an end to university contracts with a Planned Parenthood clinic that performs abortions.

The school's undergraduate population is 79 percent white and 8 percent black. The state is about 83 percent white and nearly 12 percent black.

The Associated Press contributed to this report.

Click for more from the Columbia Daily Tribune.