PITTSBURGH (AP) — Protests planned at Google offices around the country over the firing of an employee who questioned company diversity efforts have been postponed.

A statement Wednesday on the "March on Google" website said Saturday's protests were being canceled because of threats from what it called "alt left terrorist groups."

The planned events in Pittsburgh and eight other locations were in reaction to Google's firing of a software engineer who argued that biological differences helped explain why women are underrepresented at the company.

Protest organizers didn't respond to requests for information about the alleged threats. A Pittsburgh public safety spokeswoman said organizers had informed them "of plans to cancel and why they were cancelling," but she wouldn't elaborate.

Police departments in Mountain View, California, where Google is headquartered, and Cambridge, Massachusetts, where the company has an office, said the organizers hadn't sought a permit after announcing planned events there.

Jeremy Warnick, a spokesman for the Cambridge Police Department, said the department knew of no possible threats. "Through our various public safety partners, there were no known threats made against the March on Google here in Cambridge," he said.

Organizers said they had been unfairly characterized despite their statements denouncing "bigotry and hatred."