The United States said it could not confirm reports that Ukraine had disabled vehicles in a Russian convoy inside Ukraine and warned Moscow that any intervention into Ukraine without Kiev's permission was unacceptable.
"Even as we work to gather information, we reiterate our concern about repeated Russian and Russian-supported incursions into Ukraine," White House spokeswoman Caitlin Hayden said in a statement.
More top news
Police are appealing for witnesses after a Pagani Zonda driver's early morning crash near Chichester.
Two women accused of murdering Kim Jong-nam - the half-brother ofKim Jong-un - have revisited the scene of the attack.
It's a cloudy start for many with some rain around, mainly in the north and west