The Department of Homeland Security’s intelligence arm plans to cut nearly three-quarters of its full-time employees, shaving its Office of Intelligence & Analysis down from about 1,000 staff to just 275, according to four sources briefed on the matter.

The exact timing of the cuts remains unclear; sources tell CBS News the staff reductions have been in the works for months but were temporarily on hold because of rising tensions overseas after the recent U.S. strikes on Iranian nuclear facilities. The decision has raised concerns among the nation’s police and intelligence gathering agencies, as the U.S. reckons with a heightened threat environment.

DHS’ Office of Intelligence & Analysis — created after the September 11 terrorist attacks — is the only member of the U.S. intelligence community tasked with sharing threat information to state, local, tribal and territorial governments across the country.