Russia on Thursday opened the high-profile trial of jailed Ukrainian pilot Nadiya Savchenko, a hugely controversial case that could send ties between Moscow and Kiev to a new low.

The 34-year-old helicopter navigator faces up to 25 years in prison for her alleged involvement in the killing of two Russian journalists in eastern Ukraine last year. "The hearing started at 11 am (0800 GMT) as planned," a spokeswoman for the Donetsk city court in southern Russia, Tatyana Diyeva, told AFP.