Top Department of Homeland Security officials on Sunday defended an agency intelligence assessment warning that veterans returning from Iraq and Afghanistan could be susceptible to recruitment by right-wing extremists.

OKLAHOMA CITY — Top Department of Homeland Security officials on Sunday defended an agency intelligence assessment warning that veterans returning from Iraq and Afghanistan could be susceptible to recruitment by right-wing extremists, though one said it should have been “more tightly written and presented.”

Homeland Security chief Janet Napolitano said on CNN’s “State of the Union” that she regrets that some people took offense over the report but added that “a number of groups far too numerous to mention” were targeting returning veterans to carry out domestic-terrorism attacks.

She said the warning report, which went out to American law-enforcement agencies two weeks ago, was consistent with earlier reports.

The report, which also warned of veterans engaging in lone acts of violence, was criticized by conservatives who called it offensive and said the agency should apologize to veterans.

Deputy Secretary Jane Holl Lute, in Oklahoma City for ceremonies marking Sunday’s 14th anniversary of the bombing of the Alfred P. Murrah Federal Building, said it is wrong to characterize the report’s distribution as an attempt to insult veterans but acknowledged that “it should have been more tightly written and presented.”

Lute, an Army veteran and former assistant secretary-general of the United Nations in charge of peacekeeping operations, said the agency was taking “very seriously” the threat that right-wing domestic extremists could use the lagging U.S. economy and the election of the country’s first black president to recruit members.

The report mentioned Oklahoma City bombing conspirator Timothy McVeigh, a decorated Army veteran convicted of detonating an explosives-laden truck in front of the federal building, killing 168 people and injuring hundreds. McVeigh was executed in 2001, and his former Army buddy Terry Nichols is serving multiple life prison terms for his role in the attack.

Lute said her agency assesses all potential hazards and that the Oklahoma City bombing was “a reminder to the country that we can’t be complacent.”