Two students have been suspended after showing up at their Kentucky school on Halloween dressed as the teenage Columbine shooters.

The freshman girls, who weren’t identified by education officials, arrived at Adair County High School Wednesday in costumes similar to the clothing worn by students Dylan Klebold and Eric Harris, reported ABC affiliate WHAS-TV in Columbia.

Klebold and Harris killed 12 students and a teacher at Columbine High School in Colorado in 1999 before turning their guns on themselves.

No one initially guessed who the girls were supposed to be were until they told friends, “We’re the school shooters,” USA Today reported.

“They pretty much had on all black with fake blood on their faces,” a senior at the school told the newspaper. “At the time, it wasn’t really scary because they didn’t have weapons or anything, but the whole thing was really weird.”

The girls appeared on social media in their costumes re-enacting poses of the shooters, including after the young gunmen’s suicides. They also posted photos of themselves next to news photos of the Columbine scenes. 

The caption of one of the Instagram posts read, “Bang bang brother,” according to an image shared by WHAS-TV.

“We take the situation very seriously and our personnel are continuing to investigate the facts and circumstances surrounding this matter,” Adair County Schools Superintendent Pamela Stephens said in a statement Friday. “The students are currently suspended.”

The father of one of the girls, who said he had no idea who they were supposed to be, told a local TV station that the friends realize now they made a mistake. He said the two have received death threats.

The Columbine tragedy, which also wounded 21 students and teachers, was the worst school shooting in U.S. history at the time it occurred. Since then, a gunman at Virginia Tech killed 32 people in 2007, and a gunman killed 26 young children and staff at Sandy Hook Elementary in Connecticut in 2012. Seventeen people were killed this year at Marjory Stoneman Douglas High School in Parkland, Florida.