Poland has extradited an Austrian accused of killing unarmed civilians and captured troops in Ukraine.
Austrian authorities will identify the suspect only as Benjamin F.
He was arrested last month on a European warrant while trying to cross into Ukraine from eastern Poland.
He is suspected of committing the killings last year while fighting against pro-Russian separatists in eastern Ukraine.
Ukraine has been struggling to put down a three-year-old uprising that has killed more than 10,000 people.
Efforts to secure a lasting cease-fire have failed.