Russia warned in advance that its military would launch strikes Tuesday on Syria for the first time from a submarine stationed in the Mediterranean, the United States said.

The strikes were aimed at "two terrorist strongholds" around Raqa, the de facto Syrian capital of the Islamic State group, Russian Defense Minister Sergei Shoigu said.

Speaking in Washington, Pentagon spokesman Peter Cook said: "We were given advanced notice that they would be carrying out strikes."

He added: "We appreciate that," particularly because the Kremlin was not required to do so under a memorandum of understanding signed by Russia and the US to avoid the two sides clashing over Syria.

The advanced notice on the cruise missiles was "an additional measure of safety," said Cook.

The United States heads a coalition of some 60 countries taking part in air strikes on Syria and Iraq in a bid to destroy the self-proclaimed Islamic State group.

Moscow, a close ally of Syrian President Bashar al-Assad, is also waging an air war over Syria.

Germany to send first Tornados to back anti-IS mission
Berlin (AFP) Dec 8, 2015 - Germany will Thursday deploy two Tornado reconnaissance jets and 40 troops to Turkey to back the fight against the Islamic State group in Syria, the military said.

The personnel of 51st squadron Immelmann will leave the Jagel base in northern Germany on an A400M, followed by two of six Tornados Germany has pledged.

An A310 MRT aerial refuelling jet will also be deployed Thursday from Cologne-Wahn base to the Incirlik airbase in Turkey, the military said Tuesday.

German lawmakers last Friday authorised the deployment of up to 1,200 personnel and the aircraft to join international military operations against the IS, in support of France after the November 13 Paris attacks.

The six Tornados are fitted with surveillance technology that can take photos and infrared images, even at night and in bad weather, and transmit them in real time to ground stations.

Berlin also said it would send a frigate to help guard the French aircraft carrier Charles de Gaulle in the eastern Mediterranean.

Germany does not plan bombing runs, unlike France, the United States and Britain.

Post-war Germany has been traditionally reluctant to send troops into active combat abroad, although it has joined international missions in the Balkans and elsewhere, and the NATO coalition in Afghanistan.