Russia has begun supplying Iran with drones.

According to two sources cited by The Financial Times, senior Iranian and Russian officials started discussing drone deliveries just days after the conflict began.

Security officials believe that Iran is being supplied with Geran-2 and Shahed-136 kamikaze drones, which are based on Tehran-developed Shahed UAVs that Russia had previously used in Ukraine.

“Russia has significantly upgraded the Shahed drones, including modifying the engines, navigation systems, and electronic countermeasure protection. These systems surpass those that Iran produced domestically,” said Nicole Grajewski, a professor at Sciences Po specializing in Russian-Iranian relations.

The deliveries of munitions reportedly began three weeks after it emerged that Russia had been providing Iran with critical satellite and intelligence data to help it strike US forces in the Middle East, The Telegraph reports.