Some 170 Polish miners on Wednesday blocked train tracks near the northern border with Russia's Kaliningrad province to stop a train carrying cheaper Russian coal, the border guard service said.

"An approaching train has been stopped before getting to the spot where the miners are," a spokeswoman for the service, Agnieszka Golias, told Agence France Presse.

Pro-Russian rebels defiantly announced Tuesday they would stage their own elections in November, raising the stakes in a standoff with Kiev despite both sides moving to end five months of deadly fighting.

The prime minister of the self-proclaimed Donetsk People's Republic, Alexander Zakharchenko, said the eastern separatist region would hold elections to choose a parliament and a leader on November 2.

Poland kicks off major military exercises involving eight NATO partners on Wednesday amid the West's worst standoff with Russia since the end of the Cold War sparked by differences over the Ukraine crisis.

Organized every two years since 2006, this year's Anaconda maneuvers involve 12,500 soldiers, with 750 from NATO members the U.S. and Britain among others, the Polish defense ministry said, adding the event "has become a permanent training element of the North Atlantic alliance".

The prime minister of the self-proclaimed People's Republic of Donetsk said Tuesday that the pro-Russian rebels have removed artillery from frontline areas where Ukraine had also withdrawn, in line with a peace plan signed Saturday.

"We have withdrawn artillery but only in those areas where the Ukrainian regular units have done the same. Where Ukraine hasn't withdrawn artillery, we also haven't done so," the rebel leader, Alexander Zakharchenko told the Interfax news agency. 

The Lebanese Army's chief of Staff Maj. Gen. Walid Suleiman is scheduled to travel to Moscow next week to discuss with Russian officials military assistance to Lebanon.

Interior Minister Nouhad al-Mashnouq, who recently visited Russia, said Suleiman will follow up the meetings that he held with the Russian officials.

Prime Minister Shinzo Abe has dropped plans to host Russian President Vladimir Putin in Japan this year due to friction after Tokyo imposed sanctions on Moscow over the Ukraine crisis, reports said Tuesday.

The two countries had agreed on the Russian leader's visit "this autumn" but Washington had asked Tokyo to postpone it, Kyodo News reported, quoting Japanese government sources.

A fragile truce between pro-Russian insurgents and Ukrainian forces appeared to be consolidate Monday as clashes subsided and attention focused on the unresolved status of the separatist east.

Ukraine said it lost two soldiers in sporadic overnight raids by "armed gangs" on small towns surrounding the main rebel stronghold of Donetsk, but that nevertheless the military was preparing to pull back, as agreed under a new ceasefire deal.

U.S. Secretary of State John Kerry on Sunday raised the threat of Islamic militants in Iraq and Syria directly with his Iranian counterpart in high-level talks in New York, a U.S. official said.

Kerry met Iranian Foreign Minister Mohammad Javad Zarif for more than an hour at a hotel, during which they discussed progress in nuclear negotiations and "also discussed the threat posed by ISIL," a senior State Department official said, referring to the Islamic State group.

President Petro Poroshenko said Sunday that Ukraine must be ready to defend itself should a peace deal with pro-Russian insurgents fail.

"We must be ready to protect our country if the peace plan does not work," Poroshenko said in a nationally televised interview.

Thousands of Russians on Sunday marched through Moscow to protest against the Kremlin's involvement in the Ukraine crisis, in the country's first major anti-war rally since fighting erupted in April.

A huge column of protesters moved through the heart of the capital to condemn Moscow's role in a conflict that has claimed nearly 3,000 lives and pitted Russians against Ukrainians.