Pro-Russian rebels in eastern Ukraine seized a key coastal town on Wednesday in a move which opened a dangerous new front against the Kiev government.
Separatist forces flying the flag of the rebel Donetsk People's republic entered the coastal town of Novoazovsk, depriving Ukraine of control of its southernmost section of border with Russia and putting the insurgents within striking distance of the centre of regional government in Mariupol.
The lightning advance took place in an area tens of miles from territory previously held by the rebels, suggesting that the troops originated at least in part from the Russian side of the border.
Combined with a series of other defeats and the capture of Russian soldiers inside Ukraine on Tuesday, it increased speculation that – despite official denials – Russian regular forces have now entered the war alongside the separatists.
Kiev claimed that a vast column of "up to 100" tanks and heavy weaponsfrom Russia was later spotted moving towards Temanove, a government-held town 20 miles to the north of Novoazovs