A 15-year-old boy has been arrested after allegedly making terror threats to an East Valley high school and a mosque, according to the Mesa Police Department.

Mesa police said it was first tipped off by the FBI at about 7:30 p.m. Feb. 18 about a teen who was making threats to carry out a mass shooting at his school and a mosque.

The FBI said it had been investigating the teen since January over online comments that suggested he lived in the Valley.

Not long afterward, detectives tracked down the suspect, a student at Dobson High School. He was arrested the next day at school, but authorities said there was no threat to anyone on campus or in the community.

Investigators said the boy was specifically targeting Hispanic students at school, and the FBI said the threats were racially motivated.

Once in custody, detectives searched two homes where he lived and found items that were seen in the online posts, as well as tactical gear, a tomahawk and “extremist-related materials.” His electronics were also taken away, police said.

Authorities said he was arrested on suspicion of making a terroristic threat. Because he was sent to a juvenile detention facility, his name was not released.

“The Mesa Police Department appreciates the collaborative efforts of the FBI, school administration, school resource officers, and detectives for bringing this investigation to a swift and safe resolution,” police said in a written statement.