WASHINGTON — Intelligence assessments approved by senior leaders at U.S. Central Command exaggerated the progress of anti-terrorism efforts they ran against Islamic State militants, a House Republican task force said in an initial report released Thursday.

The report detailed what the task force described as “persistent problems” in 2014 and 2015 with the command’s analysis of U.S. efforts to train Iraqi forces and combat the extremist group in Iraq and Syria. Central Command, based in Tampa, Florida, runs the U.S. military operations in the Middle East.

The task force’s investigation isn’t yet complete. A separate investigation by the Pentagon inspector general also is underway.

A Central Command spokesman said the command is reviewing the House report but declined to comment further because the task force and inspector general inquiries are still proceeding.

‘CONSISTENTLY MORE OPTIMISTIC’

The task force focused on the command’s intelligence directorate. The office underwent structural and management changes in mid-2014 that resulted in intelligence that was “consistently more optimistic regarding the conduct of U.S. military action” than the judgments of many senior, career analysts at the command, according to the report.

The command’s intelligence on the Islamic State group also was “more optimistic” than that of other U.S. intelligence agencies and what actual events warranted, the task force said. “Additionally, many (Central Command) press releases, public statements and congressional testimonies were also significantly more positive than actual events,” according to the report.

House Republican leaders formed the task force after lawmakers learned that an unnamed analyst assigned to the command had filed a formal complaint alleging that intelligence about the Islamic State group had been manipulated.

The Republican chairmen of the House Intelligence and Armed Services committees and the Appropriations defense subcommittee established the task force.

The report said leadership at the command and within its intelligence office “deteriorated significantly” after Marine Corps Gen. James Mattis departed as senior commander in 2013. Army Gen. Lloyd Austin replaced Mattis as the command’s top officer.

Roughly a year after Austin took over, several new senior intelligence officials arrived in Tampa to replace holdovers from Mattis’ tenure. Following the fall of Mosul, Iraq, to Islamic State militants in June 2014, the new officials, who are not named in the report, increased their involvement in the review and editing of various intelligence products.

The officials “regularly performed line-in/line-out edits and wording changes which were perceived by analysts as more frequent than previous intelligence directorate leadership,” according to the task force.

Dissatisfaction with the new way of doing business is reflected in an internal survey of command analysts that described the leadership as toxic, according to the report. Forty percent of the analysts who responded to the survey, which was conducted by the office of the director of national intelligence, said they had experienced an attempt to distort or suppress intelligence in the past year, the report said.

Army Gen. Joseph Votel replaced Austin as commander of Central Command in March.

The command’s “consistently rosy view” of military success against Islamic State militants in 2014 and 2015 “may well have resulted in putting American troops at risk as policymakers relied on this intelligence when formulating policy and allocating resources for the fight,” said Rep. Mike Pompeo, R-Kan., a task force leader.