Classes at CSU Channel Islands were canceled Wednesday as authorities searched for a person who reportedly attacked a student with a gun, officials said.

The Ventura County Fire Department responded just after 11 a.m. to the Camarillo campus. Emergency medical personnel transported the victim to a local hospital after suffering injuries in the attack with the gun, Fire Capt. Brian McGrath said.

An emergency alert sent by the university informed students and faculty that a student was physically assaulted with a handgun in a bathroom on the second-story of the Bell Tower building. It also said classes were canceled and students should not come to campus. Those in the dorm rooms should remain there with the doors locked.

Nancy Gill, a spokeswoman for the university, confirmed the fire department's report and reiterated information that went out with the emergency alert to students. She said the alert was sent about 12:10 p.m.

Around 3 p.m., students received a message from campus officials stating that the suspect had not been located but that a threat no longer existed. The text said classes were to resume on Thursday.

A criminal investigation would be handled by university police, school officials said in a statement Wednesday afternoon.

The attacker was described as a woman with medium complexion, about 24 or 25 years old and wearing a gray shirt, black pants and gray Converse shoes. She was last seen fleeing the area of the attack, the university stated.

The gun was described as a silver handgun, according to the alert.

Students expressed frustration on social media that they were not notified of the incident as it unfolded.

Police Chief Michael Morris said there was a delay between the assault and the time they received their report.

Officers decided not to ask students and faculty to shelter in place or to put the campus on lockdown because they didn't have enough information initially, he said.

"Due to the circumstances in a situation like this, we provide information to the community so they can make decisions," Morris said.

He said it was rare for a gun to be reported on campus. Wednesday's was the first for the year.

No additional information was provided about the victim.

Professor Sean Anderson had just started a noon class in Sierra Hall when an automated message came over the campus emergency alert system.

Over the loud speaker of the classroom's phone, the message said an incident had happened in the Bell Tower building, about 1,000 feet away.

Everyone was told to secure their area, he said.

They closed and locked doors, but not long after, were told that afternoon classes were canceled and everyone should leave.

Anderson, who teaches environmental science, told students to go directly to their cars and to try to go in groups.

He described the scene on campus as orderly. His students didn't seem fearful, but they had serious expressions on their faces.

While the school didn't appear to use social media to make sure everyone knew of the incident, within a minute or so of the first announcement, Anderson said everyone's phones were blowing up with campus alerts.

Anderson, whose wife also teaches on campus, sent off a quick text to his son and his parents to say they were safe and leaving the school.

As the incident occurred, there was a question about whether the campus was on lockdown.

"There was no lockdown ordered because it was unclear where the suspect had fled to," Gill said.

Chase Baker, 25, was among the students who were upset with the campus' communication about the attack.

Baker and Jacob Coyle, 20, were in a calculus class in the Bell Tower building when the injured student walked in.

"We’re in class and a girl in our class staggers in, hair all wet, clothes all ruined and says she was just attacked by girl in the bathroom with a gun," Baker said.

Coyle said there's a restroom right across the hallway from the classroom but he didn't hear any screams or a struggle. The victim had water dripping from her face and she was "shaking uncontrollably," he said.

The student wasn't bleeding but had a couple marks on her forehead, Coyle said.

Coyle, Baker and a few others ran outside the classroom after the student walked in. They were looking for the attacker but couldn't find anyone.

Meanwhile, some of the female students tended to the injured student and called 911.

Students in the calculus class moved out into the hallway and watched as police interviewed the victim. Baker said he overheard the girl saying it was a random attack and there was a gun involved.

Coyle said campus police and the Ventura County Sheriff's Office were on campus after authorities were called.

Ventura County sheriff's Capt. Denise Sliva said deputies were called initially to help with the search of the suspect but were later called off. They were then called back just to beef up police presence and ensure students have peace of mind, Sliva said.

The four-year school is part of the public California State University system and enrolls just over 7,000 students and employs about 1,200. The university opened in 2002.

As of Wednesday afternoon, an event planned for children in the University Glen neighborhood near the campus was still planned as scheduled.

Staff writers Cheri Carlson and Alexa D'Angelo contributed to this report.