WASHINGTON — An FBI report on the rise of black “extremists” is stirring fears of a return to practices used during the civil rights movement, when the bureau spied on activist groups without evidence they had broken any laws.

The FBI said it doesn’t target specific groups, and the report is one of many its intelligence analysts produce to make law enforcement aware of what they see as emerging trends. A similar bulletin on white supremacists came out about the same time.

The 12-page report, issued in August, says “black identity extremists” are increasingly targeting law enforcement after police killings of black men, especially since the shooting of Michael Brown roiled Ferguson, Missouri, in 2014. The report describes cases in which “extremists” had “acted in retaliation for perceived past police brutality incidents.” It warned that such violence was likely to continue.

Black leaders and activists were outraged after Foreign Policy revealed the existence of the report last month. The Congressional Black Caucus, in a letter to FBI Director Christopher Wray, said the report “conflates black political activists with dangerous domestic terrorist organizations” and would further erode the frayed relationship between police and minority communities.

“I have never met a black extremist. I don’t know what the FBI is talking about,” said Chris Phillips, a filmmaker in Ferguson.

Before the Trump administration, the report might not have caused such alarm. The FBI noted it issued a similar bulletin warning of retaliatory violence by “black separatist extremists” in March 2016, when the country had a black president, Barack Obama, and black attorney general, Loretta Lynch.

But black voters overwhelmingly opposed Donald Trump. And they are suspicious of his administration, which has been criticized as insensitive on racial issues, including when Trump was slow to condemn white nationalist protesters after a deadly rally in Charlottesville, Virginia.

Attorney General Jeff Sessions, a former Alabama senator whose career has been dogged by questions about race and his commitment to civil rights, did not ease lawmakers’ concerns when he was unable to answer questions about the report or its origins during a congressional hearing this past week.

Sessions said he was aware of “groups that do have an extraordinary commitment to their racial identity, and some have transformed themselves even into violent activists.” He struggled to answer the same question about white extremists.

It wouldn’t be unusual for an attorney general not to have seen such an FBI assessment, which the FBI creates on its own to circulate internally among law enforcement agencies. But the exchange with Rep. Karen Bass, a Los Angeles Democrat, presented an uncomfortable moment.

Bass said she was especially concerned after receiving complaints from members of Black Lives Matter, who said they were being monitored and harassed by police in her district.