WASHINGTON • The tensions and the complexity of the Syrian civil war have been escalated by the shooting down of a Syrian warplane by a US fighter jet on Sunday and the same-day missile attack by Iran's Revolutionary Guards Corps from inside Iran at Islamic State in Iraq and Syria (ISIS) targets in Syria.
Russia's Defence Ministry said yesterday it would view as targets any flying objects over Syria in areas of the country where its air forces operate.
It also said it would now track all coalition flights west of the Euphrates River while suspending its use of a military hotline for avoiding incidents in Syrian airspace - accusing the US of failing to use the established communication hotline to warn Russia about downing the plane.
Russian Deputy Foreign Minister Sergei Ryabkov condemned the US action, describing it as an act of aggression.
"It is, if you like, help to those terrorists that the US is fighting against," Mr Ryabkov said.
Washington said the jet had dropped bombs near US-backed forces and Damascus said the plane was downed while flying a mission against ISIS militants.
It is the first time the US military has downed a Syrian aircraft since the civil war began in 2011, officials said.
Also on Sunday, Iran's Revolutionary Guards Corps launched six mid-range missiles at targets in Syria, hoping to punish ISIS forces responsible for the terror attacks in Teheran two weeks ago.
The Guards Corp said it successfully "targeted the headquarters and meeting place and suicide-car assembly line" of "ISIS terrorists" in the province of Deir el-Zour, where ISIS forces surround an estimated 200,000 people in a government-held section of the provincial capital of the same name.
The missile operation "is just a very small part of the capability of Iran's punitive force against the terrorists and its enemies", the Islamic Students' News Agency quoted Guards spokesman Ramezan Sharif as telling state TV.
"Regional and international allies of the terrorists must understand this missile operation is a warning message."
Iran had earlier insinuated that the US and Saudi Arabia - its chief regional foe - had encouraged the June 7 attacks on Iran's Parliament and the mausoleum of the late Supreme Leader, Ayatollah Ruhollah Khomeini, killing 17 people.
The Guards' missile strike sends a message that extends beyond the fighting in Syria, said non-resident fellow Amir Handjani at the Atlantic Council research centre.
It sends "a message to the Saudi-led alliance that 'our missiles have the range and the accuracy to strike anywhere in the region'".
NYTIMES, BLOOMBERG, REUTERS, AGENCE FRANCE-PRESSE