The Varshavyanka class are among the quietest in the world, according to the boasts of Russian state media.
Moscow has deployed at least two cruise-missile armed frigates and intel ships.
The Admiral Essen joins its sister vessel, which arrived after the U.S. strike on Syria.
The deployment would strongly boost Russia’s capabilities near Aleppo.
The rescued migrants from Nigeria, Ethiopia, Eritrea and Bangladesh were taken to a Sicilian port for questioning.
Mered Medhanie is believed to have smuggled thousands of people from Africa into Europe.
The refugees are believed to have set off from Libya, with 41 survivors now in Greece.
The EU ships get new powers to board, search, seize and divert vessels in the Mediterranean.
The changing weather will bring the continent new challenges.
The EU's anti-smuggling operation enters its second phase.
European ministers are meeting in Luxembourg over the weekend to discuss the plan.
About 500 people were on board two sinking ships.
Three other rescue operations underway on Monday as EU ministers present plan to double funding for Triton operation.
Greece is unable to react to Turkey's trespassing into its territory due to lack in military funding.
Over 10,000 migrants arrived in the first three months of this year.
The North African migrants were on seven vessels which were rescued in a single day this week, Italian and Tunisian authorities said on Wednesday.
The boat sent out a distress call on Tuesday, but no gunmen were found on board
Air crews raced to rescue as many of the hundreds trapped on board as possible before nightfall as storms hampered seaborne operations.
Hundreds of migrants fleeing war zones in Africa and the Middle East have drowned in the "deadliest weekend ever in the Mediterranean”, says UNHCR
More than 5,000 people were rescued by the Italian Navy this weekend as migrants attempt to cross from North Africa.