Russian Warships Said to Be Going to Naval Base in Syria

Introducing an unpredictable new element into the Syrian crisis, a news agency said on Monday that two Russian naval vessels with marines on board were ready to head for Syria to protect Russian citizens and a naval base there, in what would be the first known reinforcement of Moscow’s military presence since the start of an uprising against President Bashar al-Assad.

The Interfax news agency quoted a Russian naval official, who was not identified, as saying that the two amphibious assault ships would head for the Mediterranean port of Tartus, where Russia has its only warm-water naval base in the region. Russia has been the staunchest ally of Mr. Assad in the 16-month-old conflict, shielding the Damascus government from stern international measures to remove him from office.

Moscow is also Syria’s biggest arms supplier, and the relationship provides Russia with its main foothold in Middle East diplomacy.

Interfax quoted the official as saying the ships were “ready to ensure security of Russian citizens and infrastructure of the Russian Navy logistics base” in Tartus.

The official said the crews “jointly with the marine units they carry are capable of protecting the security of Russian citizens and evacuating a part of the property of the logistics base.”

The Russia Today English-language television news channel said the vessels were currently moored in the Crimean port of Sevastopol. Talk of evacuation of material and “protection” of Russian citizens in Syria, who include military advisers, seemed to be one more sign of alarm about the deteriorating security situation there after United Nations monitors announced over the weekend that they were suspending their operations as violence mounts.

The United Nations said the monitors would not be withdrawn from Syria, but were being locked down in Syria’s most contested cities, unable to conduct patrols. While the decision to suspend their work was made chiefly to protect the unarmed monitors, the unstated purpose appeared to be to force Russia to intervene to assure that the observers are not the targets of Syrian forces or their sympathizers. Russia has opposed Western intervention and, by some accounts, continues to arm the forces of Mr. Assad.

Activist groups in Syria on Monday reported renewed government shelling of the central city of Homs, a persistent flash point in the fighting between government forces and their armed opponents. Artillery fire also fell on the rebel stronghold of Douma near Damascus, activists said. Their reports are difficult to corroborate because of restrictions on journalists’ access.

The White House issued a statement on Saturday once again calling on Syria to uphold commitments it has made in recent months, “including the full implementation of a cease-fire.” The statement added, “We are consulting with our international partners regarding next steps toward a Syrian-led political transition” called for in two United Nations Security Council resolutions, and “the sooner this transition takes place, the greater the chance of averting a lengthy and bloody civil war.”

Last Friday, Russia’s chief arms exporter said his company was shipping advanced defensive missile systems to Syria that could be used to shoot down airplanes or sink ships if the United States or other nations try to intervene to halt the country’s spiral of violence.

“I would like to say these mechanisms are really a good means of defense, a reliable defense against attacks from the air or sea,” Anatoly P. Isaykin, the general director of the company, Rosoboronexport, said Friday in an interview. “This is not a threat, but whoever is planning an attack should think about this.”

Mr. Isaykin’s remarks came just days after Secretary of State Hillary Rodham Clinton raised diplomatic pressure on Russia, Syria’s patron, by criticizing the Kremlin for sending attack helicopters to Damascus.