Ukraine’s Defense Council says preparations are under way to retake the rebel-controlled eastern city of Donetsk — the last stronghold of heavily armed pro-Russian separatists seeking autonomy from Kyiv.

Defense spokesman Andriy Lysenko did not provide details. But he said the military has opened humanitarian corridors for city residents to flee the planned offensive, and that the government will help evacuees find temporary shelter.

As Lysenko spoke Monday, Moscow — which has demanded a halt to the Ukraine offensive near its border — launched a massive show of military strength just inside Russian territory. Russian authorities say the five-day military operation will involve 100 warplanes, helicopters and anti-aircraft batteries.

Russian officials said the military began exercises Monday in the central and western regions of the country, which would include the Ukraine border region.

The officials say the drills involving more than 100 fighter jets and helicopters will last through Friday.

While the announcement did not mention Ukraine, the military exercises could increase tensions in the already volatile region.  

The United States and its European allies accuse Russia of arming pro-Russian separatists in eastern Ukraine, as well as building up military forces along the border with Ukraine and cross-border shelling.

On Sunday, deadly clashes between Ukrainian government forces and separatists continued as investigators searched the site of the crash of Malaysia Airlines Flight 17 for a third day.

Local officials in the city of Donetsk said six people were killed there in shelling between the two sides. Three other people were killed in Luhansk. The two eastern Ukrainian cities are the last remaining significant pro-Russian separatist strongholds.

Russia to deploy peacekeepers?

Meanwhile, a spokesman for Ukraine’s National Security and Defense Council said Monday that Russia cannot unilaterally deploy peacekeeping forces in Ukraine, noting that such deployments are the “strict prerogative” of the U.N. Security Council and that both sides to the conflict must consent.

“So far, there has been no U.N. statement, nor have the sides given their consent,” Andriy Lysenko told reporters in Kyiv.

On Sunday, Lysenko reported that the Russian military had deployed 34 armored vehicles “marked with the symbols of a peacekeeping contingent” near a village in Russia’s Bryansk region on the border with Ukraine.

Late last month, U.S. Deputy National Security Advisor Tony Blinken said there had been “a significant re-buildup of Russian forces along the border, potentially positioning Russia for a so-called humanitarian or peacekeeping intervention in Ukraine.”

On Monday, Russia’s Itar-Tass state news agency quoted Russian Foreign Minister Sergei Lavrov as saying he had officially appealed to the Organization for Security and Cooperation in Europe, the Council of Europe, the International Committee of the Red Cross and the U.N. “to organize something like an international humanitarian mission” to get aid to the areas in and around Luhansk and Donetsk.

MH17 recovery efforts

Meanwhile, the remains of more victims from Malaysia Airlines Flight 17 arrived in Kharkiv Sunday to be prepared for transportation to the Netherlands.

The head of the Dutch police mission working at the crash site says crews have finished searching one of five zones of the crash site. He said completing the search will take at least three weeks.

The investigators are focusing on recovering several dozen bodies still missing more than two weeks after the Malaysian plane was shot down, killing all 298 passengers and crew. Most of the victims were Dutch.

Ukraine and Western governments blame rebels for the shootdown of the Boeing 777. U.S. analysts say the jetliner likely was downed by pro-Russian separatists launching a Russian missile, thinking the jetliner was a Ukrainian military aircraft.

Rebels intent on establishing autonomous republics near the Russian border have been battling Ukrainian troops for three months.

  conflict, donetsk, troops, Ukraine, world