MOSCOW (Reuters) - A woman who brandished the severed head of a four-year-old girl in her care outside a Moscow metro station has said she beheaded the child to avenge Muslims killed in the Kremlin’s campaign of air strikes in Syria. In video posted online on Thursday and circulated by several prominent bloggers, 38-year-old Gulchekhra Bobokulova from Muslim-majority Uzbekistan gave her first deta