The intelligence post, located 1.2 miles from the U.S. mission that was targeted by militants in a September 11 attack, was evacuated of Americans after the assault that killed Ambassador Christopher Stevens. Three other Americans died in the attacks on U.S.-occupied buildings, including two who were hit in a mortar blast at the secret compound.

The publication of satellite photos showing the site’s location and layout have made it difficult, if not impossible, for intelligence agencies to reoccupy the site, according to government sources, speaking on condition of anonymity.

The post had been a base for, among other things, collecting information on the proliferation of weaponry looted from Libyan government arsenals, including surface-to-air missiles, the sources said. Its security features, including some fortifications, sensors and cameras, were more advanced than those at rented villa where Stevens died, they said.