The two men crouched in the shade of a tree. The ballot papers they were accused of forging lay on the front of their Russian-made Moskvich car, stopped and searched by Ukrainian soldiers on the outskirts of the port city of Mariupol, in the country's rebel southeast.

"This is how they did it in Crimea," said Warrant Officer Timofey Rudyak, who, like the other soldiers had been sent 750 km (500 miles) from the capital, Kiev, to restore order to the country's industrial heartland.

Rudyak, 35, said the several hundred ballots, bound in white paper and almost all ticked "yes," had been intercepted a little over an hour after voting began in a referendum on self-rule; a vote dismissed by Ukraine's government and its Western backers as a sham, a repeat of the vote that saw the Crimean Peninsula annexed by Russia in March.