The United States is pulling out all the stops to try to detect and head off any plots to avenge the death of Osama bin Laden, top counterterrorism officials said, calling this a dangerous moment.

FBI and Homeland Security officials are on “tip-toe” status, reviewing all intelligence and aggressively pushing informants in an effort to thwart any possible retaliatory attack. Attorney General Eric Holder said he has ordered U.S. Attorney Offices across the country, and counterterrorism investigators, to review investigative files and cases because of concerns of retaliatory attacks.

“I think we will ultimately be more safe as a result of his death,” Holder said Wednesday on Capitol Hill. “But in the short term, we have some serious concerns we have to be ready to address.”