What happened next was filmed by students who recorded the confrontation from the balconies overlooking the hall. Islamic State group supporters, dressed casually and with black masks and baseball caps pulled over their faces, milled around on one side, separated from a group of left-wing students by a barricade of folding tables grabbed from the science fair. The two groups shouted at each other before hurling projectiles across the vast room.
"Security! Why are you just watching?" one student screamed over the sound of shattering glass. "Why aren’t you taking them away?"
Irem Meten, whose socialist student group, FKF, shot much of the video, says the men had no trouble getting into campus, even though entry requires university identification.
Media attention has occasionally driven hardliners into hiding. The Islamic State group "gift shop" in Bagcilar, which was in the press earlier this year, is now empty save for a few bare mannequins and a religious inscription above the door. Landlord Koksal Coskun says the occupants left after attracting negative attention from neighbors and police.
The masked attackers at Istanbul University, by contrast, show no sign of going underground, even as Turkey inches closer to joining the U.S.-led military intervention in Syria. In a statement recently published by the religiously conservative Haksoz magazine, the group claiming responsibility for the skirmishes shrugged off the threat of arrest.
"If anyone will be called to account, it will not be those who wage jihad," the statement said. "It will be the collaborators and the so-called imperialists who find refuge behind NATO, the UN, and the U.S."
The group did not return an email from AP seeking further comment.
When reporters visited the university on Sept. 30, there was an undercurrent of tension. About 20 riot police, a few carrying submachine guns and several wearing body armor, loitered outside the Literature Department. Inside, all appeared calm. Students smoked, drank tea and played ping pong. Students from the university’s women’s society were busy hand painting an anti-Islamic State group sign.
Many were defiant but some were clearly worried. Left-wing students now go to and from campus in one large group, citing safety in numbers.
"Of course we’re stressed," said Ulas Suder, a 20-year-old archaeology major. "What can you feel when an organization that terrorizes the Middle East enters your school?"