Armed pro-Russian separatists who captured the police headquarters in the east Ukrainian town of Kostyantynivka have also seized the town administration building, a spokesman for the regional government said.
"I think it's the usual demands, the same as in other towns, the scenario doesn't change: a referendum and a federal system of government," said Ilya Suzdaliev, a spokesman for the Donetsk region administration, which includes Kostyantynivka.
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Authorities have warned that the death toll is likely to rise as much of the building is yet to be searched.
The PM will sound out the possibility of new free trade agreements with Gulf states for once the UK has left the EU.
In the unexpected announcement on Monday, Mr Key said it was the "right time" to leave politics.