According to intelligence reports, Iran is procuring advanced engine technology used in drones from Chinese manufacturers. The technology is smuggled from Xiamen, in China, to Mombasa, Kenya, then sent to Salalah, Oman, from where the technology is sent on to Houthi strongholds in Yemen. This procurement pattern is a shift from previous efforts by Iran to obtain miniature engines from small German manufacturers, including the successful procurement of 42 twin-cylinder propeller motors in 2015 that were routed through Athens to Tehran. Such engines were found in drones used by the Houthis in attacks on Saudi Arabia. Their sale to Iran was subsequently banned by the German government. Iran has used a range of Dutch and German engines in its drones to boost domestic production.