MOSCOW - Russia sent warships to the eastern Mediterranean Sea on Tuesday, the Defense Ministry announced, in what appeared to be preparation for a possible evacuation of Russian citizens from Syria.

Russian officials began last summer to plan an evacuation, but have delayed making public announcements, analysts say, to avoid signaling a loss of confidence in President Bashar Assad, a longtime strategic ally. Moscow staunchly opposes international intervention in Syria and has blocked U.N. Security Council resolutions meant to force Assad from power. Officials said Tuesday that Russia's position had not changed.

Moscow, however, has signaled in recent days that it sees Assad's forces losing ground, and that it is beginning to prepare for a chaotic transition. One immediate concern is the large number of Russian citizens in Syria, as a result of decades of intermarriage and longstanding economic ties.

Late on Monday, Russian diplomats said that two Russian citizens had been kidnapped by an armed group. The Russians -- evidently workers in a privately owned steel factory -- were seized as they traveled between Homs and Tartus and were held for ransom. An Italian citizen, Mario Belluomo, was abducted along with them.

Then on Tuesday, the Russian Defense Ministry announced that a flotilla of five ships -- a destroyer, a tugboat, a tanker and two large landing vessels -- were being sent from Baltiysk, a port in the Baltic Sea, to relieve ships that have been in waters near Syria for months. A second group was sent from Severomorsk, in northwestern Russia. At typical cruising speeds for such vessels, both groups would arrive about the beginning of January.

A naval official, speaking on the condition of anonymity, told the Interfax news service that the ships were "on their way to the coast of Syria for possible participation in the evacuation of Russian citizens" to a Russian port on the Black Sea.

The official said that the mission had been planned swiftly but under conditions of total secrecy, and that the timeline for the ships' return to port "depends on the development of the situation in Syria."

Alexandr Shumilin, a regional analyst and a foreign correspondent, said Russian leaders had avoided taking steps toward evacuation until now to avoid signaling that Moscow intended to abandon Assad, but that they also risked public anger if Russians became targets of violence in Syria.

"It appears that some break has taken place, but whether that means a change of policy, or a modification of policy, that's hard to say," said Shumilin, who is head of the Middle East conflict analysis center at the Russian Academy of Science's Institute for Canada and the United States.

"The decision-makers are now concentrating on humanitarian questions, the protection of Russian citizens."