WASHINGTON/RIYADH – Iranian drone attacks on CIA facilities in the Persian Gulf have prompted U.S. intelligence analysts to investigate whether Russia assisted by providing targeting information or advanced drone technology, said four people familiar with U.S. intelligence.

These people, who spoke on condition of anonymity to discuss national security matters, said U.S. intelligence officials have not yet reached firm conclusions about the possible Russian involvement in the attacks on CIA facilities. But they cited the strikes’ effectiveness and apparent ​precision, as well as Russia’s broader technical support for Iran, as possible evidence.

It has been previously reported — and U.S. officials have acknowledged — that Russia has ‌provided targeting ‌and other support for Iran in its strikes on U.S. targets in the Gulf region generally, but the intelligence community’s ​investigation of possible Russian involvement in supporting the CIA facility attacks has not been previously disclosed. At least two CIA sites were struck in March, it has been reported. One of the facilities was the CIA station in Saudi Arabia, which is located in the U.S. embassy in Riyadh, and a separate ⁠site was located in eastern Iraq. Some of the sources said additional CIA sites had been hit, but they did not disclose details.