A school in Waukegan, Illinois, was put on lockdown Tuesday after several students reported seeing clowns taunting them outside. Students said one clown had a knife, one had a briefcase, and the third one seemed to have a gun, though it’s not clear whether the weapons were real or props, police said. “The children also reported that the clowns threatened to return Friday to kill them,” Commander Joe Florip of the Waukegan Police Department told local media. Nick Alajakas, spokesman for Waukegan Community Unit School District 60, said the school was recently mentioned in social-media posts about the creepy clowns. “It’s all part of this national thing going on with creepy killer clowns,” Alajakas said. Police in two other cities—North Chicago and Round Lake—said they were increasing patrols of local schools after “clown-related” threats were made on social media. Reports of clowns threatening children have spread across the country in recent months, first in the Carolinas and Georgia, before spreading to New York, Texas, and now the Chicago area.