A number of cruise missiles launched from a Russian ship and aimed at targets in Syria have crashed in Iran, two U.S. officials told CNN Thursday. Monitoring by U.S. military and intelligence assets has concluded that at least four missiles crashed as they flew over Iran. One official said there may be casualties, but another official said this is not yet known. It’s unclear where in Iran the missiles landed. The Russian ships have been positioned in the south Caspian Sea, meaning the likely flight path for missiles into Syria would cross over both Iran and Iraq.

The Russians have been firing a relatively new cruise missile called “Kaliber,” using it for the first time in combat. Iran’s semi-official FARS news agency, however, said that neither Russian nor Iranian authorities have confirmed the U.S. officials’ information at this point. The assessment came as Defense Secretary Ashton Carter warned Thursday at NATO headquarters in Brussels that Russia would likely suffer casualties “within the coming days” as it deepens its military involvement in Syria. CONTINUE