LVIV, Ukraine (Reuters) - Over 7,000 Russian servicemen have been killed since the start of Russia's invasion of Ukraine, while hundreds have been taken prisoner including senior officers, a military adviser to Ukrainian President Volodymyr Zelenskiy said on Wednesday.

       A Russian army commander was taken to Belarus after being severely wounded, adviser Oleksiy Arestovich said in a televised briefing.

       (Reporting by Pavel Polityuk; Writing by Alessandra Prentice; Editing by Mark Heinrich)