Armenian forces on Thursday killed an Azerbaijani soldier in the latest breach of a ceasefire between the arch-foes locked in a simmering conflict over the disputed Nagorny Karabakh region, officials in Baku said.

"Armenian forces have yet again violated the ceasefire and killed an Azerbaijan army warrant officer," Azerbaijan's defence ministry said in a statement without giving further details.

Poland's prime minister on Wednesday criticized a fiercely nationalistic Russian biker gang's plans to ride through Europe to celebrate the Soviet Union's victory over Nazi Germany in World War II. 

The two-week 6,000-kilometer (3,750-mile) rally by Russian bikers including the Night Wolves, a motorcycle club backed by Russian President Vladimir Putin, comes as tensions run high between Russia and the West over the crisis in Ukraine.

Russia can expect international sanctions against it to be lifted only when it complies with the terms of a ceasefire with Ukraine, foreign ministers from the Group of Seven said on Wednesday.

The top diplomats, gathering in Germany for their second meeting since the expulsion of Russia from their ranks last year over its annexation of Crimea, said the truce agreed in February in the Belarussian capital of Minsk must be respected.

Dutch and international investigators will renew their search for body parts and debris at the MH17 plane crash site in restive eastern Ukraine, including at a location previously considered unsafe, the team's chief announced Wednesday.

"The team is in Donetsk and ready to start tomorrow (Thursday)," Pieter Jaap Aalbersberg said at a press conference in The Hague.

Russia on Wednesday canceled the release of a Hollywood thriller set in the Stalin era on grounds it distorts history and would be shown as the country celebrates the Soviet Union's victory over Nazi Germany in WWII.

The film, "Child 44", starring Tom Hardy, Vincent Cassel and Gary Oldman, tells the story of a serial killer who targets children in the Stalin era. It is based on a fantasy novel by English writer Tom Rob Smith and was due to go on wide release in Russia on Thursday.

British fighter jets were scrambled on Wednesday in response to the sighting of two Russian military aircraft near UK airspace, hours after three Russian ships were monitored as they entered the English Channel. 

"Quick Reaction Alert Typhoon fighter aircraft were launched today after Russian aircraft were identified flying close to UK airspace," said a Ministry of Defense (MoD) spokesman.

Prime Minister Benjamin Netanyahu expressed Israel's "grave concerns" Tuesday over Moscow's decision to lift a ban on supplying Iran with sophisticated S-300 air defense missile systems.

In a telephone conversation with Russian President Vladimir Putin, he warned that such a step "would only increase Iran's aggressiveness in the region and would undermine the security of the Middle East," his office said.

Estonian Prime Minister Taavi Roivas on Tuesday urged allies to send over more troops to the region, calling on Germany to take the lead in the effort amid security fears over Russia.

"Estonia sees that a more long-term stationing of European allies in Estonia and the Baltic region could be led by Germany," Roivas said after meeting with German Defense Minister Ursula von der Leyen in Tallinn.

Turkey on Tuesday launched construction of its first nuclear power plant which Ankara hopes will open a new era of greater energy self-sufficiency, but the ceremony was marred by angry protests against the controversial $20 billion project.

After the launch ceremony, dozens of environmental protesters converged on the iron gates of the site in Akkuyu in Mersin province on the shores of the Mediterranean.

Three Russian ships including a destroyer have entered the English Channel and are being monitored by Britain's Royal Navy as they pass through, the Ministry of Defense said Tuesday.

It is the latest in a string of similar incidents and comes at a time of tense relations between London and Moscow over the crisis in Ukraine and the inquiry into the death of Russian ex-spy Alexander Litvinenko.