MIAMI (AP) — The latest news on threats sent to school districts around the country. All times eastern:
A third suburban Indianapolis school district has canceled classes after receiving a threat.
The Franklin Community Schools south of Indianapolis issued a statement saying it canceled Friday classes after receiving a "serious" threat and consulting with police. It says the validity of the threat received Thursday afternoon remained in question.
The statement did not disclose the nature of the threat, but Superintendent David Clendening told the Johnson County Daily Journal that police dogs were searching the Franklin Community High School after a caller reported a homemade bomb in a locker room area. The school also tweeted that it was on lockdown.
The district says it will resume classes Jan. 5.
Two school districts west of Indianapolis canceled Thursday classes after officials said threats were made against their schools.
School officials in Las Vegas say they received a threat similar to ones reported by districts from Miami to San Francisco, but didn't close campuses at the nation's fifth-largest school district.
A Clark County School District spokeswoman says administrators discovered an emailed threat after 9 a.m. Thursday similar to those received this week in Los Angeles, New York, Houston and other cities.
She says officials deemed the threat "less than credible."
The district sent a letter to parents saying principals and school staff had been asked to stay alert and keep students calm and focused on learning.
It says it has crisis plans in place and police trained to detect and respond to threats.
The district has 356 campuses and more than 320,000 students.
San Francisco officials say schools there have received a threat similar to ones in Los Angeles, New York and Dallas this week.
Officials with the San Francisco Unified School District said Thursday that officials deemed the threat not credible. Schools are open Thursday.
Authorities say they inspected all schools and found nothing suspicious. Police presence is increased at schools around the district, which has 57,000 students.
Other school districts around the country reported receiving similar threats. Most schools also determined that the threats were not credible and went on with classes as scheduled.
The developments come on the heels of Tuesday's districtwide closure in Los Angeles, sparked by an email threatening a large-scale attack. New York City schools received a similar threat, but officials there concluded it was a hoax.
A South Texas school district near the border with Mexico received an email threat Wednesday night but determined the message was a hoax, and classes went on as scheduled Thursday.
An emailed statement from the McAllen Independent School District to parents said it appears the district received the same threatening email that earlier targeted schools in New York and California. The statement says the South Texas district "was able to trace the email to the same server that was used" in those two sets of hoaxes. The Texas district did not elaborate.
The statement said several current and former school trustees received the message Wednesday night via their board email addresses.
The McAllen ISD, with about 25,000 students and 33 campuses, was working with the FBI and other law enforcement Thursday in the investigation into the hoax threats. Extra police officers were being stationed at McAllen schools, with increased patrols, as a precaution.
Districts in Orlando, Florida, and Long Beach, California, have joined the list of school systems that received email threats that were deemed to be "less than credible."
Orange County Superintendent Barbara Jenkins said during a news conference Thursday in Orlando that the email was sent to the district's general email late Wednesday. Law enforcement was notified and checked it out, and then schools opened Thursday morning. Jenkins says principals in the nation's 10th largest school district have been asked to stay alert and keep students calm.
Officials in Long Beach say the district received an email threat similar to the ones in other cities. Schools opened for the district's 79,000 students on Thursday. Long Beach is adjacent to Los Angeles, where the nation's second-largest school district shut down Tuesday out of caution after receiving an emailed threat.
Houston school district police Chief Robert Mock says nothing unusual has been found following email threats that prompted random searches of schools.
Mock says explosives detecting dogs and extra patrols responded after the email was received Wednesday night. He says so far everything is normal Thursday and kids are in school.
He says the threat was received by the superintendent and other people in the school district. The messages were similar to those sent to Los Angeles and New York City earlier this week. Emails were also sent to school systems in Miami, Fort Lauderdale and Houston.
Mock says he doesn't want to downplay the message because "a threat is a threat." He says the email referred to weapons and explosives among unsophisticated content that was "so far over the top the logistics just didn't pan out."
Two central Indiana school districts canceled Thursday's classes after officials said threats were made against their schools.
Danville Community School Corporation canceled classes following alleged threats, including threats from two students who've been arrested.
The nearby Plainfield Community School Corporation just west of Indianapolis also canceled classes due to a threat "directed to the high school."
Danville Police Chief William Wright says a 14-year-old freshman and a 17-year-old sophomore were arrested early Thursday after the boys allegedly made threats against Danville schools in separate incidents.
Wright says a third threat posted on social media early Thursday and apparently "tied to the Plainfield School Corporation threat" had prompted Danville schools to cancel its classes.
Danville Community School Corporation Superintendent Tracey Shafer says the individual making the threats against Danville schools may have also threatened Plainfield schools.
This item has been corrected to show that police say the 17-year-old who was arrested is a sophomore, not a senior.
The Dallas Independent School District received a similar threat to the ones sent to Miami, Fort Lauderdale and Houston school officials on Wednesday night.
The district announced on its website that schools were opening Thursday after an emailed threat sent to several school district staff and teachers at Pinkston High School and Martinez Elementary School was deemed non-credible. The emails were sent Wednesday night.
District officials were immediately notified and the school system's police department activated its emergency protocol. They're working with law enforcement agencies to make sure students are safe.
Schools in South Florida and Houston also opened Thursday with extra security on hand.
Officials say the emails are similar to ones received earlier in the week in Los Angeles and New York City.
School officials in Miami, Fort Lauderdale and Houston say they're beefing up security on campuses after receiving threats similar to the ones received by the Los Angeles and New York school districts earlier this week.
The Miami-Dade County Public Schools and Houston Independent School District announced on their websites that "less-than-credible" threats were received late Wednesday evening. Both school districts plan to open as usual Thursday.
In Miami, school district police immediately contacted law enforcement agencies and decided to open schools.
In Houston, officials said law enforcement officers were making sweeps of school district buildings to ensure student safety. They encouraged parents and students to be vigilant Thursday morning and report any suspicious activity to police.
In a tweet sent Thursday morning, Broward County Public Schools in South Florida also said a threat had been received, but students should report to school as usual.