The BND federal intelligence service had told German lawmakers about its suspicion in a confidential briefing late last week, reported the Bild am Sonntag newspaper without citing named sources.

In the briefing, the BND reportedly warned that IS fighters possess portable rocket launchers captured from Syrian army stocks. Some dated from the 1970s, while others were modern and advanced.

The shoulder-mounted rocket launchers -- known as Man Portable Air Defense Systems or MANPADS -- were of Russian design but may have been manufactured in other countries including Bulgaria or China, the report said.

According to The New York Times, ISIS used missiles like Chinese-made FN-6 shoulder-fired missile against Syrian and Iraqi helicopters.The FN-6 is a copy of the French Mistral missile.

Turkeys’ Hurriyet newspaper claimed that a U.S. Air Force F-15 fighter suffered damage during an air strike on ISIS in Iraq on Aug. 21. According to the newspaper, Turkish F-16s met up with the damaged F-15 and escorted it to an emergency landing at Batman air base in southern Turkey.

Also the Wall Street Journal quotes high-level Arab diplomatic sources as saying that Saudi Arabia will provide advanced, shoulder-fired anti-aircraft and anti-tank missiles to mercenary forces in Syria via Jordan, and that Saudi Arabia and the USA continue to pay millions of dollars for the mercenary’s salaries.