IOWA CITY, Iowa (AP) — Police are seeking a 17-year-old on attempted murder charges following a shooting early Sunday in a nightlife district near the University of Iowa campus, authorities said Wednesday.

Five people were treated for gunshot wounds, including three University of Iowa students. One woman remained in critical condition Wednesday after sustaining a life-threatening injury to her head, Iowa City Police Chief Dustin Liston said.

Officials said an arrest warrant was issued for the 17-year-old who was allegedly engaged in the fight, adding that reports indicate as many as 40 people may have been involved. Officers had been dispatched to the fight and arrived within 45 seconds, Liston said.

After walking away from the other participants, the suspect allegedly fired six times into the crowded pedestrian area, Liston said. Iowa City’s downtown pedestrian mall is lined with shops, bars and restaurants.

The minor from Cedar Rapids, Iowa, will initially be charged as an adult, as is required by Iowa law for forcible felony charges against an individual aged 16 or older, said Rachel Zimmermann Smith, Johnson County attorney.

The charges, which include five counts of attempted murder, will be brought when the suspect is apprehended, she said.

Liston said the investigation is ongoing and additional charges are expected. About three dozen search warrants have already been executed.

“We will continue to work tirelessly to hold those responsible fully accountable,” he said, adding that anyone with information on the incident or the suspect are encouraged to come forward.

The five victims were not “targets of the shooting,” Liston said. “We have no reason to believe they were otherwise affiliated with the fight that preceded the shooting.”

Liston also provided details about the other four victims’ injuries, including one struck in the arm and chest, two struck in one or both legs and one in the side of their stomach. One is still hospitalized in stable condition and three have been released, he said.