At least three people were killed and 30 others wounded in six separate shootings near major US university campuses following a violent Halloween weekend marked by homecoming celebrations and football rivalries.

At least six people were wounded around 11 p.m. when a gunman opened fire on a crowded downtown street in Newark, Delaware, near the University of Delaware. Students in Halloween costumes fled as the shots rang out.

Near Michigan State University in East Lansing, a gunman wearing a Michael Myers mask opened fire and wounded one person, Metro Detroit News reported. A second person was injured in a separate shooting at about 12:30 a.m. Sunday. Authorities had not determined whether the incidents were connected.

At the University of Colorado Boulder, police said a gunman shot and killed a 19-year-old student and wounded another at a large house party attended by hundreds of students at about 11:30 p.m.

Police identified two suspects and said they believe the men tried to force their way into the party roughly 90 minutes after officers had shut down the gathering and instructed attendees to leave.

In Birmingham, Alabama, one person was killed and eight others were wounded—one critically—in multiple shootings following Saturday night’s 85th Magic City Classic football game. The annual rivalry pits Alabama A&M against Alabama State, two historically Black universities.

Police Chief Michael Pickett described the violence as “two senseless acts of violence.” Witnesses reported chaotic scenes at a tailgate outside Birmingham’s Legion Field shortly before 8 p.m. Saturday, AL.com reported.

Authorities detained one person in connection with the shooting.

Near Illinois Wesleyan University in Bloomington-Normal, Illinois, a 19-year-old woman was killed and seven other people were wounded.

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One victim was hospitalized in critical condition. WGLT reported that two Illinois Wesleyan students and one Illinois State University student were among those injured.

At least seven people—four men and three women—were wounded in a shooting on Kirkwood Avenue near Indiana University’s Bloomington campus at about 1:30 a.m. Sunday.

Officers reported hearing “multiple gunshots” after an argument broke out among a large crowd of Halloween revelers in the popular bar district, Deputy Chief of Police Ryan Pedigo told WTHR.

The victims, who ranged in age from 17 to 27, were not students and were not from Bloomington.

Police took an 18-year-old into custody but did not say whether he was the shooter. An AR-15-style handgun was also recovered at the scene.

Officers found another weapon, an AK-47-style pistol, on one of the victims, police said.

Investigators recovered shell casings in multiple calibers at the scene.

Indiana University had been celebrating homecoming and an overtime victory over the Minnesota Golden Gophers earlier Saturday, alongside the weekend’s Halloween events.