CROCKER, Mo.– The Crocker R-II school district went on lockdown Wednesday after police said they received a possible threat to the district.

On June 22, the school district went into lockdown at 9:15 a.m., with students released around two hours later. The district also cancelled the two remaining days of summer school “out of an abundance of caution,” according to a post to the Crocker High School Facebook page.

Crocker Police Department said in a press release that the security of the school was maintained by Crocker PD and the Pulaski County Sheriff’s Department, while deputies followed up on leads outside the city limits.

Crocker PD said an investigation into the threat is still ongoing.