LOS ANGELES (AP) — A 44-year-old man was in custody Wednesday on suspicion of phoning in bomb threats to five Los Angeles schools earlier this year, while separate threats against Northern and Southern California high schools led to the arrests of two students, authorities said.

Marcus James Buchanan, who lives in Oklahoma but grew up in Los Angeles, is charged in a federal criminal complaint alleging he threatened to bomb five Los Angeles campuses and shoot children as they exited one of the elementary schools, the U.S. Attorney's Office said in a statement.

It wasn't immediately known if Buchanan had an attorney and contact information for the Blackwell, Oklahoma resident could not be found.

In February and April, prosecutors say, Buchanan phoned in multiple threats that led to lockdowns at Los Angeles schools.

During one phone call, Buchanan allegedly told an employee: "There is a bomb at your school and we will shoot the kids when they get out of the school. That is what you get for not accepting me in ’86," according to an affidavit.

Phone records indicated that the threatening calls came from a number identified with Buchanan, the affidavit states.

Separately, Berkeley police said Wednesday that officers arrested a 16-year-old boy after receiving a tip that he had been recruiting other students to participate in a mass shooting or bombing at Berkeley High School in the San Francisco Bay Area. A search of the teen’s home yielded parts to explosives and assault rifles, several knives, and electronic items that could be used to create more weapons, Berkeley police said on Twitter.

The teen surrendered to police Monday and was arrested on suspicion of possessing destructive device materials and threatening to commit a crime that would result in death or great bodily injury.

The arrests come a week after a gunman killed 19 children and two adults at Robb Elementary School in Uvalde, Texas.

In Southern California, authorities said an unnamed juvenile who attends Sierra Vista High School in Baldwin Park was arrested on suspicion of emailing a threat involving explosive devices on campus.

The investigation began May 25 when staff received the threatening email after classes had ended for the day, police said in a statement Tuesday.

A large police response, including explosives-detection canine teams from many agencies, they did not find any devices on the campus 15 miles (24 kilometers) east of Los Angeles.

The police statement said that staff again received threats on Tuesday and detectives, with technical assistance from the FBI, identified the suspect, arrested him and seized evidence from his home.

“Detectives will seek criminal prosecution for these threats,” the police statement said.

The school announced on its website that in addition to a police presence, staff would search students’ backpacks and belongings through the last week of the current semester.

Meanwhile, administrators at Orange County’s Mater Dei Mater Dei High said Tuesday that the school would be closed through the end of this week after a threat against the campus.

Santa Ana police said Wednesday that the threat from a former employee did not rise to the level of a criminal offense. No arrests were expected, officials said.