Syrian US-backed forces seize last route into Raqqa

At least 15 ISIL fighters were also killed in the raid, the UK-based monitor, which tracks developments in Syria's long-running conflict via a network of contacts on the ground, said.

According to the fighters of Kurdish YPG, the tunnels were found in residential buildings and connected houses where ISIS members stored weapons and protected themselves from air strikes launched by the Military intervention against ISIS.

Rami Abdelrahman, the director of the Syrian Observatory for Human Rights (SOHR), a United Kingdom -based group with an extensive network of sources on the ground in Syria, said the Arab-Kurdish coalition known as the Syrian Democratic Forces had "completely" encircled the ISIS de facto capital.

The lack of rapid progress is due to ISIS's intensification of attacks, the Syrian observatory quoted a source on Sunday.

The US has previously presented attacks on these forces as "self-defense", because they argued the pro-government forces are too close to a US-backed rebel base at al-Tanf, and even shot down a Syrian plane in "collective self-defense" when it bombed an ISIS-held town that was being advanced on by Kurdish forces.

"Russians have a lot of air defenses, they're not exactly defenseless by any means", Lamrani told Business Insider, "But the U.S. has very heavy air superiority".

"We can understand and recognize concerns of our ally Turkey", says Dillon.

It comes as it is announced a US-backed operation by Syrian forces to capture Raqqa from ISIS will start in the coming "few days".

Russian Federation and Syria have previously carried out airstrikes against the Islamic State in that region.

Washington launched a retaliatory cruise missile strike days later against a Syrian airbase from where it said the chemical attack was launched, the first direct United States action against the Syrian regime.

A spokesman for the US -led coalition told The Associated Press that the Syrian Democratic Forces are now in control of all high-speed routes into Raqqa from the south.

Russian Federation has great air-to-air fighters that could give USA jets lots of problems, but not many of them.

Two Syrian monitoring groups, Deir Ezzor 24 and Justice For Life, say the weapons were dropped by an unidentified jet over Doblan, a village on the Euphrates River.

A spokesman for the USA mission to defeat IS said on Twitter the SDF had this week cleared almost 20 square kilometers of territory once held by IS jihadists, and that the SDF "now control all high-speed avenues of approach" into Raqqa.

The move has angered North Atlantic Treaty Organisation ally Turkey, which says the Kurdish militia force YPG is linked to separatists of the Kurdistan Workers' Party (PKK) who have waged an insurgency since 1984, killing more than 40,000 people inside Turkey.

  • Joey Payne