Ukraine's president approved a disputed anti-graft measure on Thursday that could see up to a million civil servants with alleged links to past Soviet or pro-Russian governments immediately sacked.

The so-called "lustration law" follows the example of other eastern European nations that broke free of decades of Moscow's domination at the end of the Cold War.

The foreign ministers of Russia and the United States -- which are locked in a deeply antagonistic row over Ukraine -- are to meet in Paris next Tuesday, according to the Russian foreign ministry.

"In accordance with an earlier agreement, Russian Foreign Minister Sergei Lavrov will meet U.S. Secretary of State John Kerry in Paris on October 14," a foreign ministry spokesman was quoted as saying by Russian news agencies.

Russia on Thursday said that any plan to set up a buffer zone in Syria, as urged by Turkey, would need to be approved by the United Nations.

"The U.N. Security Council must take the decision on such zones," Russian foreign ministry spokesman Alexander Lukashevich was quoted as saying by the Interfax news agency.

One of the people on the Malaysia Airlines flight MH17 shot down in Ukraine in July was found wearing an oxygen mask, the Dutch foreign minister and prosecutors said, raising the possibility that some passengers might have known their plane was doomed.

"You know that somebody was discovered wearing an oxygen mask and had time to put it on," Foreign Minister Frans Timmermans told a talk show on national television late Wednesday.

A group of 22 Russians, Ukrainians and Belorussians held in Libya for three years on suspicion of fighting for deposed ruler Moammar Gadhafi have returned home after being freed, Russia's foreign ministry said Tuesday.

But Libyan authorities said there had been no decision to free the men and they were looking into whether they might have escaped from jail.

More than 330 people have been killed in Ukraine since a fragile truce began a month ago, with five million people affected by continuing violence, the United Nations said Wednesday.

A report from the U.N. rights agency also found that before the September 5 ceasefire, pro-Russian rebels in eastern Ukraine had seen their numbers significantly bolstered by an influx of foreign fighters, including apparently Russian citizens.

Ukraine dispatched top envoys to Washington and Brussels on Wednesday to secure help in the face of a surge in clashes with pro-Russian insurgents that saw six more die overnight.

A Chechen suspected of involvement in a deadly attack on a Russian police convoy in 2009 has been detained with a group of Syrian migrants off Greece, police said Tuesday.

The 34-year-old man, picked up by coastguards in the Aegean Sea early Sunday, faces an international arrest warrant for "participation in an illegal action and the murder of five police officers in Russia," according to a statement.

Ukraine appealed to Western powers for support as its truce with pro-Russian rebels seemed increasingly in tatters with 12 deaths reported Tuesday in the separatist east.

The toll was one of the highest reported since the signing of the September 5 truce agreement, and brings the number of civilians killed in sporadic mortar and rocket attacks to 14 since the weekend.

Russian President Vladimir Putin marked his 62nd birthday roaming the Siberian wilderness on Tuesday, as supporters compared his takeover of Crimea to a Herculean labor and 100,000 marched in Chechnya in his honor.

Kremlin spokesman Dmitry Peskov said Putin had taken a day off from his "extremely intense" schedule to celebrate his birthday in the depths of Siberia.