KIEV - Kiev accused Moscow on Friday of seeking to trigger a “third world war” as military tensions soared in east Ukraine and US President Barack Obama led a diplomatic charge against Russia.
A rocket-propelled grenade blew up a Ukrainian military helicopter sitting on the tarmac at a base near the eastern town of Kramatorsk, officials in Kiev said. The pilot escaped but was wounded. Smoke spewed into the sky over the rebel-held town.
The brazen attack by the insurgents came amid an army offensive to dislodge pro-Kremlin gunmen who are holding a string of eastern towns.
US President Barack Obama and top European leaders urged Moscow to stop its “intimidation” of Ukraine and raised the prospect of fresh sanctions, France said Friday.  “The heads of state and government have called for a rapid reaction by the G7 and raised the prospect of new sanctions by the international community against Russia,” the French presidency said in a statement. Kiev announced Friday that its forces were now seeking to “blockade” rebels inside another flashpoint town, Slavyansk, to prevent militant reinforcements arriving. An AFP journalist saw heavily armed troops setting up a checkpoint some 30 kilometres (18 miles) from the city of 110,000 people.
On Thursday, Ukrainian armoured vehicles and commandos had made a brief but dramatic incursion into Slavyansk, killing one 22-year-old insurgent. A rebel manning a roadblock in the town vowed that, if the army returned, “We will defeat them and we won’t take any prisoners”.
Russia responded by ordering its troops massed on Ukraine’s border to launch a new military exercise, with its foreign minister Sergei Lavrov claiming that Kiev’s offensive was part of a US plot to “seize” Ukraine for its own “geopolitical ambitions and not the interests of the Ukrainian people”.
The developments prompted German Chancellor Angela Merkel to call Russian President Vladimir Putin to voice “great concern” over the situation and to urge implementation of an accord signed in Geneva a week ago that was meant to defuse tensions.
Merkel’s spokesman told reporters in Berlin that Russia faced the threat of further sanctions: “In case nothing changes, it is important to be prepared for more”.
Germany’s foreign minister, Frank-Walter Steinmeier, warned: “There is not much time to end this madness.”
Ramping up the Cold War-style rhetoric, Ukrainian Prime Minister Arseniy Yatsenyuk accused Russia of trying to spark a global conflict. “The world hasn’t forgotten the Second World War and Russia wants to start a third world war,” he said. “Russia’s support for the terrorists in Ukraine constitutes an international crime and we call on the international community to unite against the Russian aggression.”
US Secretary of State John Kerry said the Kremlin was trying to “actively sabotage the democratic process through gross external intimidation” and described the latest Russian drills as “threatening”. “Let me be clear: if Russia continues in this direction, it will not just be a grave mistake, it will be an expensive mistake,” he said.
With the threat of further sanctions hanging over Russia, Standard and Poor’s on Friday downgraded its credit rating to one notch above junk status. Russia’s central bank reacted by raising its key interest rate in a bid to offset “growing inflationary risks”. Meanwhile, Lavrov complained about the allegations from his US, British and French counterparts that Russian agents were orchestrating events in eastern Ukraine.
“‘Sergei, you have to pull back the troops, you have to remove your agents, no one in the world believes you Russians are not there in the southeast and that you have not had your hand in all of this,’” he quoted the Western diplomats as saying. “It’s very hard for me to react,” he said, dismissing the claims.
Ukraine’s acting President Oleksandr Turchynov has pledged to push on with the “anti-terrorist” offensive to put down the rebellion in the east.
“We will not back down from the terrorist threat,” Turchynov said in a televised address Thursday, telling Russia to stop interfering in Ukraine’s internal affairs.
Yulia Tymoshenko, a former prime minister who is a frontrunner for a May 25 presidential election in Ukraine, publicly warned Putin that if he starts a war, it “will be the end of your regime”. “We shall win and your people will answer for all the crimes,” she said on her official website.
While Obama has ruled out sending US or NATO forces into Ukraine, Washington has begun deploying 600 US troops to boost NATO’s defences in nearby eastern European states.
France also said it was sending four fighter jets to join NATO air patrols over the Baltic states.
Oil prices, which rocketed up on the tensions Thursday, fell back slightly on Friday. Stockmarkets remained nervous.
“Both sides keep drawing red lines.... Traders are worried that someone ends up stepping over one of them,” said a London analyst, Jonathan Sudario of Capital Spreads.
Russia, which supplies gas to Ukraine and to many EU countries, has said it can weather US sanctions but warned they would trigger a tit-for-tat cycle which no-one would win.
The United States and the European Union have already targeted Putin’s inner circle with visa and asset freezes and imposed sanctions on a key Russian bank.
Some EU states fear that further sanctions could hamper gas supplies from Russia and undermine a fragile European economic recovery, although Russia remains reliant on gas sales with its economy tipped to plunge into recession this year.
Russia saw capital outflows in the first quarter of 2014 double from a year earlier to $50.6 billion (37 billion euros) over the uncertainty created by the Ukraine crisis and fears of greater sanctions.

The International Criminal Court’s chief prosecutor has opened an initial probe into crimes committed before and during the fall of Ukraine’s ousted president Viktor Yanukovych, the court said on Friday.
If the court launches a full probe, it would be the first outside the African continent, where governments have often accused the ICC of targeting only their leaders.
“The prosecutor of the ICC, Fatou Bensouda, has decided to open a preliminary investigation into the situation in the Ukraine to establish whether... the criteria for opening a (full) investigation are met,” the court said in a statement.
“The prosecutor shall consider issues of jurisdiction, admissibility and the interests of justice,” before deciding on a full investigation, the ICC added, saying the initial investigation was opened “as a matter of policy”.
“If there was a reasonable basis for an investigation, it is then up to her (Bensouda) to ask the court’s judges for authorisation,” ICC spokesman Fadi El Abdallah told AFP.
Ukraine earlier this month accepted ICC jurisdiction to probe alleged crimes committed between November 21, when pro-EU demonstrations erupted in Kiev, and February 22, when Yanukovych was ousted.
Kiev has not signed up to the ICC’s founding Rome Statute, but can ask for a probe to be opened.
Its parliament called in February for the ICC to prosecute Yanukovych for the “mass murder” of protesters in Kiev calling on him to stand down, a crisis that has sparked the current Ukraine-Russia standoff.
So far Bensouda has opened initial probes in Afghanistan, the Central African Republic, the Comoros, Colombia, Guinea, Honduras, the Korean peninsula and Nigeria.
Based in The Hague, the ICC opened its doors in 2003 and is the world’s first independent court set up to try the worst crimes including genocide and war crimes.