A UN special envoy has cut short his mission to Crimea after he was threatened by gunmen who told him to get out of the region where Ukraine and Russia have been locked in a tense stand-off.
At first Robert Serry tried to reason with them but was forced to take cover in a nearby cafe in the region's main city of Simferopol from where he called UN Deputy Secretary-General Jan Eliasson to tell him what had happened.
He then made his way - his car surrounded by an angry mob shouting "Putin! Putin!" - to the airport without being given the chance to collect his luggage from his hotel and got a seat on the first flight out.
Reports suggested he was headed to Istanbul in Turkey, but would be returning to Kiev.
Initial reports by Ukraine's foreign ministry that the experienced Dutch diplomat had been kidnapped were immediately denied by the UN.
Mr Serry was met outside a naval HQ by a "number of unidentified armed men" who said he should "leave Crimea" and go to the airport, said Mr Eliasson. He said Mr Serry felt "seriously threatened".
Elsewhere, around 2,000 pro-Russia protesters have retaken a government building in Donetsk, eastern Ukraine's major city, and restored the Russian flag atop.
They stormed the building on Monday and erected the Russian flag on the roof. But Ukrainian police cleared the building on Wednesday following reports it was booby-trapped with explosives.
Sky's Chief Correspondent Stuart Ramsay, in Donetsk, said several hundred well-armed riot police were guarding the building, but after a few exchanges, they stepped aside to allow the protesters in.
There were clashes when around 5,000 pro-Kiev protesters, chanting "down with Putin! Donetsk is Ukraine!", held a rally in the city's central square and were charged by about 1,000 pro-Russian supporters shouting "Russia! Russia!".
Seven people were injured and one taken to hospital after police officers on the streets were unable to keep the two groups apart.
Donetsk - which rejects Kiev's authority - was the political support base of Ukraine's ousted president, Viktor Yanukovych.
The demonstrators had been demanding the severing of ties with Ukraine's new government and said control of the police and security forces should be handed to them.
The heightened tension comes after Russian soldiers took over a Ukrainian naval air base in Saki, western Crimea, as the gravest post-Cold War stand-off between the West and Moscow continued.
Beforehand, they allowed Ukrainian servicemen to remove four MI-8 helicopters and three planes and fly them to Mykolaiv in mainland Ukraine.
Russian forces also seized two Ukrainian missile defence battalions in the Crimea region, Russia's Interfax news agency quoted a military source as saying.
The Black Sea peninsula is now under complete control by pro-Moscow forces although Russian President Vladimir Putin insists there are no Russian troops there.
Around 100 pro-Russian protesters have also marched on the headquarters of observers from the Organisation for Security and Co-operation in Europe (OSCE) in Crimea.
In Perevalnoe, southern Crimea, Ukrainian troops remain blocked inside their barracks.
Sky's Andrew Wilson, at the scene, said: "The stand-off remains as it has done for the past couple of days.
"But there are signs that people are getting used to each other - the Russian soldiers outside the barracks, the pro-Russian militia guarding in front of the gates, the Ukrainian soldiers within."
He said politicians from Kiev have been visiting the area to persuade residents to back Ukraine's new government, but "people are nervous about which way Crimea is going to go".
Russian Foreign Minister Sergei Lavrov insisted Moscow has no authority over troops that have taken control of Crimea.
"If they are the self-defence forces created by the inhabitants of Crimea, we have no authority over them," he said. "They do not receive our orders."
The Pentagon, meanwhile, announced the US would be doubling the number of US fighter jets as on a Nato air patrol mission in the Baltics with the deployment of an extra six aircraft.
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