Three Jewish institutions in Massachusetts, including two primary schools, were targeted Tuesday morning by a sixth wave of bomb threats that have affected more than 130 Jewish institutions across the United States since January.

The Solomon Schechter Day School in Newton, MetroWest Jewish Day School at Temple Beth Sholom in Framingham, and New England office of the Anti-Defamation League in Boston received the threats. No bombs were found.

These latest bomb threats affected some 15 institutions in Massachusetts, Illinois, Wisconsin, Maryland, Oregon, Florida, Alabama, and New York, and Canada, according to the Jewish Telegraphic Agency, a nonprofit news organization.

Solomon Schechter Day School’s lower school campus, which includes children in kindergarten through third grade, was evacuated after a bomb threat was received by phone about 9:50 a.m., according to Newton police.

About the same time, a staff member of the MetroWest Jewish Day School received a call warning that a 20-pound pressure-cooker-style device “would cause great carnage,’’ said Lieutenant Stephen Cronin of the Framingham police.

Cronin said the staffer who took the call thought it was prerecorded or computer-generated, like many of the other calls across the country. The school’s 60 or so students in kindergarten through eighth grade were evacuated for about an hour until the building was deemed safe.

“We were very thankful for all the local authorities. They took [the threat] seriously, they came immediately, and they were great on site,’’ said David Levinson, president of Temple Beth Sholom in Framingham, which hosts MetroWest Jewish Day School.

The Anti-Defamation League’s New England chapter in Boston was among four league offices across the country also targeted Tuesday. The staff did not evacuate, given the widespread nature of the threats, said Robert Trestan, executive director of the league’s Boston office, adding that Boston police responded and gave the all-clear.

“First and foremost is safety and security, but we also have to send the message to the people trying to intimidate us that we’re not going to be intimidated, we’re going to go about our daily business,’’ Trestan said.

“It’s important for the Jewish community to stand firm that we will continue to send our children to Jewish day schools, we will continue to use the JCCs, and we will support Jewish organizations that do work for everyone in the community,’’ he said.

At a press briefing Tuesday, White House spokesman Sean Spicer invoked the opening words of President Trump’s recent address to a joint session of Congress: “We’re a country that stands united in condemning hate and evil in all of its forms. We denounce these latest anti-Semitic and hateful threats in the strongest terms.’’

Spicer said that as long as such incidents continue, “We will continue to condemn them and look at ways in which we can stop them.’’

Federal authorities arrested a former journalist, Juan Thompson, 31, in St. Louis last week on a cyberstalking charge in connection with some of the threats. Officials said they believed Thompson was trying to harass his former girlfriend by framing her for the threats.

Levinson said a letter about the threat was sent to Temple Beth Sholom’s 200 or so families Tuesday. He described the mood as somber.

“After they made a break in the case, I was hoping they would die down,’’ he said. “But that wasn’t the case.’’

Material from the Associated Press was used in this report. Globe correspondent Maddie Kilgannon contributed to this report. Lisa Wangsness can be reached at lisa.wangsness@globe.com.