At least 10 Jewish community centers across the United States were targeted with bomb threats on Monday, for the fourth time in five weeks.

The threats have been called in to JCCs across the country, according to Paul Goldenberg, the director of Secure Community Network — an affiliate of the Jewish Federations of North America that advises Jewish groups and institutions on security.

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News reports indicated that threats were received by JCCs in Whitefish Bay, Wisconsin; St. Paul, Minnesota; Houston, Texas; Milwaukee, Wisconsin and Birmingham, Alabama.

The threats were called in on Monday morning. It is not known if they were live calls or recorded.

“It appears to be the same serial caller” as inthe prior incidents, Goldenberg told JTA.

Goldenberg said that some of the JCCs were evacuated and others were not.

“The JCCs are very well equipped to handle this,” he said.

Goldenberg did not confirm where any of the threats occurred, saying they took place across the country and that his office “is monitoring the situation.”

Goldenberg said the fact that the threats were made on Presidents Day, when more people might be in the buildings during the daytime, does not appear to be a factor in the threats.

Last week, President Donald Trump was asked during a news conference about the prior JCC bomb threats and what the government’s response would be to “an uptick in anti-Semitism.” Although the reporter did not suggest Trump was anti-Semitic, the president answered by denying he is an anti-Semite and called the question “insulting.” Trump says he is the 'least racist person'

The  Harry and Rose Samson Family Jewish Community Center in Whitefish Bay, Wisconsin was evacuated at about 10:30 a.m. on Monday, and reopened at about 3 p.m., an hour after police and FBI officers said that everything was clear, according to local reports. A message on the JCCs website read: “The JCC is currently closed and safely evacuated.” It is the second time in recent weeks that the JCC has been evacuated due to a bomb threat.

The Jewish Community Center in St. Paul, Minnesota, including an early childhood program, also was evacuated on Monday morning, according to Minnesota Public Radio. The students at the center were moved to a nearby fire station while police cleared the building and investigated.

On Jan 31, some 17 JCCs across the United States were targeted with bomb threats. On Jan. 18, some 30 Jewish institutions in at least 17 states received bomb threats. On Jan. 9, such threats were called into 16 JCCs across the Northwest and South, forcing the evacuation of hundreds.