Staff working for Serhiy Taruta, the steel baron appointed by Kiev as governor of the restive Donetsk region, say he is hard at work in the regional capital, but cannot disclose where, exactly, for security reasons.

The governor is in an "operational headquarters suitable for wartime," said Taruta's spokesman, Alexander Omelchuk.

Those unusual working arrangements reveal an uncomfortable truth for the Western-backed government in the capital, Kiev: Its control over the Russian-speaking Donetsk region in the east of the country is so fragile it is almost nonexistent.