ATLANTA (AP) — The first day of fall semester brought fear to Clark Atlanta University, where students worried about their safety the day after gunshots were fired into a crowd of 200 people outside the school's library.

Four students were wounded by gunfire after an argument broke out between two groups at a block party shortly after 10:30 p.m. Tuesday, Atlanta police said. The injured women were all expected to recover.

"It could have been any of us," Zaire Hammond, a senior from Sacramento, California, said Wednesday along the main walkway across campus. "Stuff like this shouldn't happen on a school campus."

The shooter escaped in the chaos outside the library that serves students from Clark Atlanta and other nearby historically black colleges, and no arrests had been made by late Wednesday, Atlanta police said.

The block party was celebrating the end of new student orientation, and Clark Atlanta student Anais LaFontaine of New York City said Wednesday that she's concerned about the first-year students.

"I don't want them to be scared to come back," she said.

Other students say they want security strengthened on the campus near downtown Atlanta that's easily accessible to the public.

"Anybody and everybody can walk through here," said Jada Phillips, a student from Virginia.

School officials did not immediately respond to requests for comment regarding students' concerns about security.

On Wednesday, there was a heavy security presence on campus as groups of students discussed the shooting as they walked past the library. A couple of Atlanta police officers also stood on a corner across the street.

Police spokesman Carlos Campos released video of a male suspect who authorities want help identifying.

The gunshots began after an argument broke out between two parties and someone opened fire, investigators said. Video aired by WXIA-TV shows dozens of students running frantically after the gunshots.

"It appears there were two separate groups that were targeting each other, and these people were just caught in the crossfire," Atlanta police Capt. William Ricker told reporters.

Two of the victims are 18-year-old students at Spelman College, a nearby all-women's school. Investigators believe the other two women are 18-year-old and 19-year-old Clark Atlanta students, police said.

Clark Atlanta's Office of Religious Life announced a prayer vigil for Wednesday evening.

"Evil will not have its way on our campus," it said on social media.

"We are asking our faculty to be aware and prepared to support those students experiencing the effects of this incident," Clark Atlanta interim President Lucille Maugé said in a message to students.

Atlanta police routinely work with Clark Atlanta's police department, as they do with campus police at other schools in the city such as Georgia State University and the Georgia Institute of Technology.

"We're always very much aware when school is open at the campuses inside the city of Atlanta and we do make a concerted effort to work closely with the campus police, and make sure we properly patrol our areas," Campos said.