(VOVworld) – On Thursday, Russian news agency RIA Nvosti quoted a spokesperson for the Russian Air Force as saying that a Russian S-400 air defense missile system has been delivered to Russia’s Khmeimim air base in Syria.

The S-400 anti-aircraft missile system on display in Russia. (CC BY-SA Соколрус/Wikimedia)

On Wednesday, Russian President Vladimir Putin accepted the Defense Ministry’s proposal to deploy the system. The move took place a day after Turkish fighter jets shot down a Russian Su-24 bomber, which had been taking part in Russia's anti-terror campaign in Syria.

Addressing a cabinet meeting on Thursday, Prime Minister Dmitry Medvedev said Russia approved military and diplomatic measures in retaliation for the downing of the Russian bomber by Turkey.

Medvedev said the Russian government will take a series of retaliatory actions including stopping economic cooperation projects, restricting financial and trade transactions, adjusting import-export tariffs, and imposing tourism, transportation, and humanitarian aid restrictions. The duration of these measures will depend on future developments.

Turkey's Foreign Ministry summoned the Russian ambassador in Ankara on Thursday to complain about protests outside Turkish missions and businesses in Russia.

Protesters in Moscow hurled eggs and stones at the Turkish Embassy on Wednesday, breaking windows in the compound. Police cleared the area and made some arrests shortly after the protest began.