On October 30, 2013, police fired teargas at protesters engaged in a non-violent, on-campus protest at the University of Abuja.  In addition, police reportedly barricaded all entrances to the university, and at least one lecturer was taken to the hospital and treated in connection with inhalation of the teargas.
The protest was part of a nation-wide strike, which had been going on for four months, brought by the Academic Staff Union of Universities to demand that the government address issues of decaying infrastructure at Nigeria’s universities.
Scholars at Risk is concerned about the apparent use of disproportionate force by police against academic personnel engaged in the non-violent exercise of protected human rights, including free speech and association.  In addition to the harm to the immediate victims, such incidents have a chilling effect on academic freedom and undermine democratic society generally.  That harm is compounded when such attacks occur on campus, thus undermining institutional autonomy.
Sources:

http://www.vanguardngr.com/2013/10/asuu-strike-police-tear-gas-protesting-uniabuja-lecturers/
http://allafrica.com/stories/201401100546.html
http://premiumtimesng.com/news/147566-asuu-strike-police-teargas-protesting-uniabuja-lecturers-disrupt-peaceful-rally.html