Boston authorities sought to quell fears Tuesday after reported bomb threats forced the cancellation of public school classes in Los Angeles. New York City education officials received similar threats, but decided to continue with classes.
Mayor Martin J. Walsh said the City of Boston experienced a cyber attack that began about 9 a.m. Tuesday and lasted 20 minutes, causing an Internet outage at city agencies. Walsh's technology czar, Jascha Franklin-Hodge, stressed that the outage was akin to vandalism and not terrorism.
"We understand there are concerns right now, given the recent events," Walsh said. "The outage that we received today has no specific connections to threats in Los Angeles or in New York. We have received no credible threats."
Police Commissioner William B. Evans appealed for calm at a time of elevated fears following terrorism attacks in Paris and San Bernadino, Calif. He said law enforcement officials work hard to substantiate claims, ensure they are credible, and then take action. He said the city had seen an increase in reports of unattended backpacks and other similar alerts.
Last year, he said Boston police received an overseas threat targeting two city schools, but those threats turned out to be nothing, Evans said.
"I just want everyone to know we are on top of things," Evans said. "The city is safe. We have to remain calm."
Tommy Chang, superintendent of Boston public schools, said school authorities will continue to monitor for dangerous activities.
"At this time, we have no reason to think there are any threats toward Boston or our schools or any of our agencies,'' Walsh said. "I want all our parents, teachers, and residents to know our city is safe. And our schools are safe."
Meghan E. Irons can be reached at meghan.irons@globe.com. Follow her on Twitter @MeghanIrons.