Turkish Prime Minister Ahmet Davutoglu on Tuesday called on Russia to re-establish dialogue channels instead of making "baseless accusations" of an alleged oil trade between Ankara and Islamic State (IS) jihadists.

"We should sit at the table and discuss what to do instead of making baseless accusations," Davutoglu told reporters at Ankara airport before leaving for a visit to the Turkey-backed breakaway region of northern Cyprus.

Turkey on Saturday warned its citizens off non-urgent travel to Russia in the latest tit-for-tat move as the two nations square off over Ankara's downing of one of Moscow's warplanes.

The foreign ministry in Ankara said travel to Russia should be avoided a day after Moscow -- which had earlier urged its nationals to leave Turkey -- announced it was scrapping its visa-free regime for Turkish visitors.

A leading Kurdish lawyer was shot dead Saturday in southeast Turkey after unknown attackers opened fire on a gathering in the mainly Kurdish province of Diyarbakir, triggering a shootout with police, hospital sources and witnesses said.

According to witnesses, unknown assailants opened fire on Tahir Elci and 40 other activists as they were giving a press statement near a mosque in Diyarbakir's Sur district.

The army announced on Saturday the arrest of a Lebanese national and a number of Syrians and Palestinians, who were being illegally smuggled to Turkey.

It said that they were arrested overnight as they were attempting to travel to Turkey by boat from the northern city of Tripoli.

Russia's Foreign Minister Sergei Lavrov on Friday said that Ankara has crossed the line by shooting down a Russian warplane this week and warned the incident could severely undermine Turkey's interests.

"We believe that the Turkish leadership has crossed the line of what is acceptable," Lavrov said at the start of talks with Syrian counterpart Walid Muallem in Moscow.

Over 1,000 protesters on Friday staged a demonstration outside the Istanbul premises of the opposition Cumhuriyet newspaper against the arrest of the paper's two journalists, accused of spying over a news report.

The protesters who included journalists and opposition MPs chanted slogans: "Shoulder to shoulder against fascism," and "Tayyip thief, Tayyip liar, Tayyip killer," referring to Turkish President Recep Tayyip Erdogan.

Turkish Prime Minister Ahmet Davutoglu on Friday sought to ease tensions with Moscow over the downing of a Russian warplane over Syria, and said the world must unite to defeat the Islamic State group.

Russia ordered sweeping retaliatory measures after Turkish fighter jets shot down the warplane on Tuesday, threatening ties between two rival players in the Syrian war and raising fears of a wider international conflict.

French President Francois Hollande and Russian leader Vladimir Putin agreed Thursday to coordinate strikes against Islamic State, but differences over Syria's future hampered efforts to bring Russia into a wider alliance to fight the jihadists.

Putin indicated France and Russia would swap data to help identify IS targets in Syria, as opposed to other groups opposed to the country's leader, Bashar Assad.

Russia's foreign ministry on Thursday urged nationals currently in Turkey to return home after tensions with Ankara soared over the downing of a Russian warplane.

"In connection with the existing terrorist threats on Turkish territory, we once again recommend that Russian citizens refrain from visiting Turkey, and recommend that Russians who are there for personal purposes return home," the foreign ministry said in a statement.

Turkey's minister of European Union affairs said Thursday that Brussels had agreed to open a new chapter in stalled membership talks with Turkey by mid-December, following an EU-Turkey summit this weekend.

"The decision to open the Chapter 17 by mid-December has been taken," Volkan Bozkir said in the capital Ankara.