The C.I.A. had been tracking Iran’s Supreme Leader, Ayatollah Khamenei for months, gaining more confidence about his locations and his patterns.

Then the agency learned that a meeting of top Iranian officials would take place on Saturday morning at a leadership compound in the heart of Tehran. Most critically, the C.I.A. learned that the supreme leader would be at the site, The New York Times reports, citing anonymous sources.

The United States and Israel decided to adjust the timing of their attack, code-named “Operation Epic Fury,” in part to take advantage of the new intelligence, according to officials with knowledge of the decisions. The information provided a window of opportunity for the two countries to achieve a critical and early victory: the elimination of top Iranian officials and the killing of Ayatollah Khamenei.

Iran’s armed forces chief of staff, Abdolrahim Mousavi, was also reportedly among those killed in the U.S.–Israeli airstrikes.

The attacks, described as a “tactical surprise,” had been planned by Israeli officials for months.

Fighter jets took off from Israel on Saturday morning and reached Tehran shortly before 10 a.m., striking the fortified government complex where officials had gathered.

Senior officials and Khamenei were located in two separate buildings within the compound, both of which were destroyed in the strikes.