Russia will release the next installment of its $15-billion loan to Ukraine at the end of the month, a newspaper close to President Viktor Yanukovych said Monday, following talks between Ukraine's leader and his Russian counterpart.

The bailout was promised to Ukraine in December after Yanukovych rejected an EU trade and political pact in favor of closer ties with Russia, a move that triggered widespread protests and led to the resignation of the prime minister.

Dozens of people marched through central Kiev on Sunday pledging their support for Russia's top opposition television channel Dozhd (TV Rain), which is threatened with closure.

Several providers have recently dropped the independent Internet and cable channel -- known for its critical coverage of President Vladimir Putin -- from their television packages in what the station has called a campaign of intimidation.

Protestors in Ukraine readied for a fresh mass demonstration Sunday as they ratcheted up the pressure on embattled leader Viktor Yanukovych to appoint a new pro-Western government and take a more conciliatory approach towards the European Union.

After a blessing by religious leaders, rock music blared out on Kiev's Independence Square -- where protesters have been camping out for months -- ahead of the demonstration due to kick off at midday (1000 GMT) in the brisk cold.

Two worshipers were killed and six injured on Sunday when a man opened fire during a prayer service in a cathedral on Russia's Far East island of Sakhalin, police said.

The man, who worked as a security guard at a private firm, was detained after the shooting and his motives were not immediately clear, Russia's Investigative Committee said in a statement.

U.S. Secretary of State John Kerry and his Russian counterpart Sergei Lavrov on Saturday discussed next week's fresh round of talks between Syria's warring sides after Damascus finally agreed to attend.

The two foreign policy chiefs "spoke about the situation in Syria in the context of the direct talks due to restart in Geneva on February 10" during a phone call, the Russian foreign ministry said in a statement without giving more details.

Ukraine on Saturday launched a terror probe into a bid by an apparently drunk man to force an airliner flying to Turkey to land in Sochi where leaders gathered for the opening of the Winter Olympic Games.

"We have launched an investigation into an attempt to commit an act of terror and an attempt to hijack a plane," Ukrainian Security Service (SBU) investigative department chief Maxim Lenko told reporters.

Ukraine's embattled President Viktor Yanukovych returned to protest-hit Kiev on Saturday after holding private talks with his Russian counterpart and ally Vladimir Putin about a suspended Moscow bailout loan.

The late Friday chat on the sidelines of the opening ceremony of the Winter Olympic Games in Russia's Black Sea resort of Sochi came amid intensifying pressure from the opposition on Yanukovych to cede some of his broad powers and appoint a new pro-Western government.

Russian television chief Konstantin Ernst admitted that TV pictures of the Olympic rings glitch at Friday's opening ceremony were doctored but that it was an open secret.

The ceremony, beamed to an estimated TV audience of two billion, got off to a rocky start when one of five illuminated snowflakes suspended above the Fisht stadium and that were supposed to morph into the five Olympic rings failed to materialise.

Japan's Prime Minister Shinzo Abe struck a conciliatory tone Friday at an unusually low-key annual rally demanding the return of islands occupied by Russia, hours before he left for the Winter Olympics in Sochi.

Abe will attend the opening ceremony of the Games in southern Russia later Friday where he will also meet President Vladimir Putin, the latest step in an increasingly close working relationship.

An adviser to Russian President Vladimir Putin accused Washington on Thursday of financing and arming Ukrainian militants as a senior U.S. official arrived for crisis talks in Kiev.

Putin's economic adviser Sergei Glazyev, often seen as the Kremlin's pointman on Ukraine, also suggested that Russia had legal grounds to intervene in the two-month-old crisis, describing the situation at attempted coup.