FILE PHOTO: The sign for the new Sandy Hook Elementary School at the end of the drive leading to the school is pictured in Newtown, Connecticut, U.S. July 29, 2016. REUTERS/Michelle McLoughlin/File Photo

(Reuters) - A bomb threat prompted the evacuation of a Connecticut elementary school on the site of the deadliest public-school shooting in U.S. history on Friday, the sixth anniversary of the massacre, police said.

Sandy Hook Elementary School in Newtown, where 26 children and educators were killed in 2012, received a threatening phone call around 9 a.m. EST, said police Lieutenant Aaron Bahamonde.

“It was a bomb threat over the phone,” Bahamonde said. About 400 people were evacuated, he said. No bomb was found.

Bahamonde said the threat was unrelated to a Thursday incident in which hundreds of schools, businesses and buildings across the United States and Canada receive email bomb threats demanding payment in cryptocurrency. Authorities dismissed those threats as a hoax.

On Dec. 14, 2012, a 21-year-old gunman killed 20 young children and six educators at Sandy Hook before taking his own life. The building where the massacre took place was torn down, and Sandy Hook students now attend classes in a new facility.

The mass shooting inflamed the long-running U.S. debate on gun rights, which are protected by the Second Amendment of the U.S. Constitution.

The United States has experienced a string of deadly mass shootings since that attack, including one at a high school in Parkland, Florida, in February that left 17 people dead.