Kuwaiti media reported on Thursday that over the past month, Israeli Air Force (IAF) Adir F-35 stealth fighters penetrated Iranian airspace twice without being detected by the cutting-edge Russian anti-aircraft systems.

Citing “an informed source”, Al-Jarida, an Arabic-language Kuwaiti daily newspaper, reported that the two IAF warplanes passed undetected over Syria and Iraq. If true, this would mean the US-built F-35  was not picked up by the S-400 anti-aircraft system installed at the Russian Khmeimim Air Base air base in Latakia, Syria. Jerusalem Post reported the F-35’s circled at high-altitude, targeting the Iranian cities Bandar Abbas, Esfahan, and Shiraz, all associated with Iran’s nuclear program.

The article in Al-Jarida also noted that the seven IAF F-35 fighters have already conducted several missions over Syria and on the Lebanese-Syrian border. It was also emphasized that new stealth fighters can fly from Israel to Iran twice without refueling.

This comes in the wake of the first direct hostile contact between Israel and Iran. Last month, an Israeli Apache helicopter shot down an Iranian drone that was launched from Syria. Israeli F-16’s struck 12 targets in Syria in response, including the Iranian base that launched the drone. One Israeli F-16 was shot down and the two pilots were injured. Several military and aviation websites have conjectured that F-35’s were used operationally for the first time by the IAF in these airstrikes inside Syria.

The news comes one week after the Israeli government admitted publicly for the first time that IAF F-16’s had destroyed the Osirak nuclear reactor in Iraq in 1981.