The mayor of Ukraine's second-largest city was fighting for his life after a daylight assassination attempt and an eruption of street violence in Donetsk dragged the east of the country towards chaos.
Gennady Kernes, a pro-Russian politician who has been mayor of the eastern city of Kharkiv since 2010, was jogging when he was shot in the back.
The attempted murder came as pro-Russian militia seized police buildings in yet another town in the Donetsk region, consolidating their hold on a strategic highway around the town of Slaviansk.
Later, pro-Russian protesters armed with bats attacked a pro-Ukrainian march in Donetsk, leaving at least five people taken to hospital with head wounds. Trouble started at 6.30pm local time as more than 1000 pro-Ukrainians gathered for a march in the centre of the industrial city.
Police largely stood by as a mob of several hundred pro-Russian activists, some armed with metal bars and baseball bats, ambushed the march from behind shortly after it began, attacking marchers and journalists.
After the clash, in which protesters from both sides were injured, the pro-Ukrainian marchers fled, leaving a large pro-Russian crowd prowling the streets and forcing some riot police to lay their shields on the ground.
Kernes was taken to hospital after a bullet punctured one lung and his liver.
He suffered a serious abdominal injury from a single shot, but was operated on successfully, it was later reported.
Kernes is a member of former President Viktor Yanukovych's Party of the Regions. He was a vocal opponent of the pro-European protest movement that brought down Yanukovych in February. He has since vacillated between support for the pro-Russian movement and backing the new Government in Kiev.
Mikhail Dobkin, the Party of the Regions' presidential candidate and a former governor of Kharkiv region, said he believed the gunman had been aiming to kill.
The United States launched a tough new round of targeted economic sanctions against the cronies of Vladimir Putin yesterday as it attempted "to ratchet up the pressure" on the Russian President and deter him from invading Ukraine.
The Kremlin vowed it would deliver a "painful" response to the sanctions imposed on 17 Russian businesses and seven individuals, including Igor Sechin, boss of the oil giant Rosneft, which is 20 per cent owned by BP.
As the share price of both companies slipped on the news yesterday, senior Obama Administration officials warned that any incursion into Ukraine by Russian forces would trigger potentially devastating sanctions against sectors of Russia's economy.
Jacob Lew, the US Treasury Secretary, declared Russia's "dangerous and inflammatory" actions in Ukraine to be "illegal and illegitimate".
Sergei Ryabkov, the Russian Deputy Foreign Minister, said Moscow would respond to the US actions. "We are certain that this response will have a painful effect on Washington," he told the Interfax news agency.
Europe was expected to follow the US lead today when it announces it will introduce asset freezes and travel bans on a further 15 Russians close to the Kremlin, after ambassador-level talks yesterday.