Three different Long Beach area schools were under investigation after multiple threats made by students were reported, according to police.

A 16-year-old boy was arrested Wednesday at Wilson High School, a 15-year-old boy was arrested Wednesday at Long Beach Millikan High School and police determined there were no credible threats to Long Beach Polytechnic High School, where another threat was made.

The investigation involving the 16-year-old junior was prompted after students reported threats they had overheard from their classmate. Police were called at about 2:30 p.m. and they interviewed numerous witnesses, searched through social media and increased patrol at Wilson High School.

A few hours before that investigation – at a school just 10 minutes away – police were called at 11:15 a.m. to Millikan High School after staff reported a threat from a freshman. Students reported the 15-year-old boy to staff, who then called officials.

No injuries were reported in either case.

On Tuesday, however, officials concluded that a threat of a shooting at Long Beach Polytechnic High School was not credible.

Superintendent Chris Steinhauser said that there is no evidence that all three incidents were related. Officials strongly encourage everyone to report threats if they hear of them or read them online.

Anyone with information regarding the threats is asked to call Violent Crimes Detectives at 562-570-7250. Those who would like to submit an anonymous tip can do so by contact LA Crime Stoppers at 1-800-222-8477 or by visiting here.