More than half a dozen Jewish community centers in the U.S. and schools in London received bomb threats Monday. There were no known connection between the threats as of Monday afternoon. At least one police department in New Jersey was contacted by the FBI, said Tenafly Police Department Chief Robert Chamberlain. The FBI did not immediately confirm any investigation into the threats. 

The Jewish community center in Tenafly is one of many across the United States that received a threat but was cleared by police within a few hours. In Jacksonville, Florida, a center also received a threatening call at about 11:10 a.m., according to News 4 Jacksonville. The Jewish Community Alliance was evacuated, but was later reopened. The Jacksonville Sheriff's office said it would work with the national Joint Terrorism Task Force to "reach out both regionally and nationally after incidents such as this to determine if they are isolated or could be a part of a larger campaign," said Christian Hancock, public information officer at the Jacksonville Sheriff's office.

Two threats occurred within five minutes of each other in Miami. The Miami Beach Jewish Community Center received a threat at about 10:45 a.m., according to Miami 7 News. It was evacuated, but police deemed it safe in the early afternoon. The Miami-Dade Fire Rescue evacuated over 500 people -- mostly children -- at the second center, the Alper Jewish Community Center. Alper received the bomb threat at about 10:40, the Miami Herald reported, but police did not find any explosive devices. 

Authorities also gave the all-clear to the Jewish community center in Columbia, South Carolina. The center was evacuated around 11:30 a.m., the local newspaper reported.

In Nashville, Tennessee, the threat was reported at 10:30 a.m. About 80 people were in the building at the time and the building was evacuated, reported the Tennessean.

A Jewish community center in Rockville, Maryland, evacuated mid-day after it, too, received a phone threat. The center was later reopened, according to reports.

The New Castle County Police Department in Delaware tweeted that it was investigating a bomb threat at the local community center at 12:52 p.m. The scene was cleared nearly two hours later.

Police searched three school sites in London for bombs after the schools received threatening calls around 10:30 a.m., but they didn't find anything, reported the Jewish Chronicle. The schools were on lockdown but not evacuated.  A few non-Jewish schools aso received threats.