MIAMI-DADE COUNTY, Fla. – Two South Florida JCC's were among a reported group of 15-19 Jewish centers in the U.S. that received bomb threats and were forced to evacuate Monday.

Children were evacuated from the Alper JCC school in southwest Miami-Dade after reports of a possible explosion that authorities later learned was a bomb threat.

The incident was reported shortly before 11 a.m. at the school at 11155 SW 112th Ave.

Miami-Dade Fire Rescue officials said 450 students and 70 employees were evacuated as a precaution.

Miami Beach police said they were also called to the Jewish Community Center at 4221 Pine Tree in response to a bomb threat. After police searched the building, they found no threat and gave the all-clear to return inside.

Police said the threats were phoned in before 10:45 a.m. and JCC employees contacted authorities.

Police said the Miami Beach JCC only handles before school care and after school care, and only a handful of people were inside at the time of the call.

K-9 units checked the building to make sure it was safe and a Miami-Dade police SWAT team checked the southwest Miami-Dade building.

Some students were picked up by their parents as they waited outside the school.

"It is disheartening to begin 2017 with hate being called into Jewish Institutions," ADL Florida Regional Director Hava L. Holzhauer said in a statement. "Make no mistake, these are terror acts intended to intimidate and disrupt the everyday lives of Jewish members of the community.

"We are grateful for the quick response of various law enforcement departments from across the state, which have assisted in the evacuations and clearance of the facilities impacted by these calls. We value our freedoms and inclusiveness in this country. We hope law enforcement will find the individuals responsible for these cowardly acts and bring them to justice."

The chair of the Jewish Federations of North America board of trustees says 15 to 19 Jewish community centers in at least six states have been targeted by bomb threats.

Richard Sandler told The Associated Press the number of threats investigated Monday across the South and Northeast was unusually high. Sandler says some were prerecorded calls.

No additional details about the calls were immediately available. Sandler said some of the community centers were evacuated but no explosives were found.

Four of the centers are in Florida. Bomb threats also targeted Jewish community centers and schools in central Florida and Tampa last week, but Sandler said there's no apparent link between those threats and the calls received Monday.

Sandler said the federations' security network was working closely with law enforcement to ensure safety at the community centers.

Authorities said bomb threats were also made Monday against Jewish community centers in Jacksonville, Nashville, Rockville, Maryland, and Columbia, South Carolina.

Threats against Jewish schools in Europe were also reported.