WASHINGTON — Facebook Inc. Chief Operating Officer Sheryl Sandberg said Tuesday the company needs to do more to protect its users from disinformation efforts, after researchers found Russian trolls attempted to suppress African-American voter turnout during the 2016 election.

“Facebook is committed to working with leading U.S. civil rights organizations to strengthen and advance civil rights on our service,” Sandberg wrote on her Facebook page. “They’ve raised a number of important concerns, and I’m grateful for their candor and guidance. We know that we need to do more: to listen, look deeper and take action to respect fundamental rights.”