Police have investigated bomb threats made to schools in Pelham, Newburgh, Bronxville and now also at the Rye City School District - just in the last few days.

News 12 has learned that the threats made against Pelham, Rye and Bronxville are all connected.

In Rye, police said they learned late Monday night that a threat was emailed to a teacher in the district.

While they believed it wasn't credible, the department and Westchester County's Police Bomb Squad searched all five schools in the district and their Central Administration Building Monday night into early Tuesday morning.

They said their search revealed that all buildings were clear.

Officials from the school district sent a letter to parents, like Heidy Martinez, notifying them what had happened.

"I just read the email and I was surprised to know that something like this would happen here," Martinez said.

In the letter, district officials also informed parents that there would be an increased police presence at all schools on Tuesday.

Christian Santos, a student who attends Rye High School, said the extra security made him feel safer as he attended his classes.

"It felt like a normal day," Santos said. "[I] saw some officers over here, right behind us, or just in the hallways talking to us, [and] making sure that we feel safe and that we're comfortable," Santos said.

Rye police said they've sent the email to the FBI and Westchester County's District Attorney's office.

News 12 is working to find out more about the source of all of these scares.