American warplanes are being jammed as they fly missions over Syria, preventing them from telling friend from foe on the battlefield.

General Raymond Thomas, head of U.S. Special Operations Command, said unspecified 'adversaries' were ramping up cyber attacks in the region.

He said the Air Force AC-130 gunship was 'aggressively' targeted, which could force it to abort missions and leave ground forces exposed.

American warplanes like the Air Force AC-130 gunship are being jammed as they fly missions over Syria, preventing them from telling friend from foe on the battlefield

General Raymond Thomas, head of U.S. Special Operations Command, said unspecified 'adversaries' were ramping up cyber attacks in the region

'Right now in Syria, we're in the most aggressive electronic warfare environment on the planet from our adversaries,' he said.

'They're testing us every day, knocking our communications down, disabling our AC-130s, etc.'

General Thomas made the candid remarks in his keynote address to a U.S. Geospatial Intelligence Foundation symposium on Tuesday.

He did not mention who was responsible for the jamming, but military commentators believed he was almost certainly referring to Russia.

AC-130s are frequently used as air support for U.S. special forces and American-backed rebel fighters fighting in Syria.

AC-130s are frequently used as air support for U.S. special forces and American-backed rebel fighters (pictured) fighting in Syria

One was used to kill dozens of Russian mercenaries who attacked an outpost manned by U.S. commandos and the Syrian Democratic Forces in February.

If the enemy jammed the gunship's communications or data links it could prevent them from coordinating strikes on the ground.

Even worse, the plane may not be able to target enemy forces accurately or even tell friend from foe - especially in close firefights at night where it is often used.

Disabling these systems could lead to attacks being aborted, leaving group troops without much-needed backup in the face of a larger enemy.

Such problems have in the past led to higher casualties, friendly fire, or even a hospital being accidentally destroyed.