Ukrainian police on Monday launched a terror probe into a blast in the government-controlled port of Odessa after an explosion outside a building housing a soldiers' support center.

Local authorities said the late Sunday explosion in the city of one million caused no injuries but shattered windows in the office of volunteers helping soldiers fighting pro-Russian insurgents in eastern Ukraine.

A torch-lit march held in Kiev to honor a controversial anti-Soviet resistance leader shows Ukraine is following in the footsteps of the Nazis, a senior Russian foreign ministry official said Friday.

"Torch-lit marches in Ukraine demonstrate that it is continuing to move along the path of the Nazis! And this is in the center of civilized Europe!" Konstantin Dolgov, the foreign ministry's human rights envoy, wrote on Twitter.

A convoy carrying wreckage from Malaysia Airlines flight MH17 arrived in the Netherlands on Tuesday on its way to a Dutch air force base where the doomed plane will be reconstructed.

Dutch national broadcaster NOS showed eight trucks carrying wreckage crossing the border with Germany overnight, before heading to a southern air base after the morning rush hour and under police escort.

Ukraine and pro-Russian insurgents on Tuesday were preparing to put to the test a comprehensive ceasefire aimed at calming an upsurge of violence that has eroded trust between Moscow and the West.

Uncertainty swirled around the deal in the early morning hours on what the government has dubbed "a day of silence." 

Ukrainian Foreign Minister Pavlo Klimkin stressed Thursday the need for a real ceasefire for eastern Ukraine, and not just the "hybrid" version currently in tatters.

"What we need is not just a hybrid ceasefire (for) the hybrid war. What we need is a real bilateral ceasefire," Klimkin told reporters at the start of a meeting of some 50 foreign ministers from Organisation for Security and Cooperation in Europe countries.

Ukraine authorities on Saturday banned flights to the rebel-held east of the former Soviet republic, the head of Ukraine's aviation authority said.

"Flights are banned for Russian companies to Kharkiv and Dnipropetrovsk for safety reasons," Denis Antoniuk told Agence France-Presse without elaborating.

U.S. Vice-President Joe Biden landed in Ukraine Thursday, U.S. diplomats in Kiev said, ahead of talks with the country's president and prime minister over possible increased assistance amid conflict in the east.

Biden will meet President Petro Poroshenko and Prime Minister Arseniy Yatsenyuk on Friday, the one-year anniversary of the Maidan protests.

A five-year-old girl, a mine company worker and four government soldiers were killed Friday during fighting in war-torn east Ukraine, officials said.

The child died and her mother was seriously wounded when rebel mortar fire hit a village near the frontline northwest of the major rebel stronghold of Lugansk, a military spokesman in Kiev and local officials said.

New European Commission chief Jean-Claude Juncker said Wednesday he would visit Kiev on his first trip outside the European Union, as the peace plan in Ukraine hung by a thread.

"I will be going to the Ukraine, I don't yet know when," Juncker told a press conference. "I promised the Ukrainian president (Petro Poroshenko) my first bilateral outside the EU will be in Kiev."

Elections organized and won by separatists in eastern Ukraine over the weekend were "unfortunate and counterproductive," U.N. chief Ban Ki-moon said Tuesday.