A friend of the Paris knife attacker has been arrested in the eastern French city of Strasbourg for questioning.

The attacker's parents were also detained after their son killed one person and wounded four others. Authorities say the attacker was a French citizen born in Chechnya. The 21-year old man was shot dead by police. Saturday's attack took place near the city's main opera house. Witnesses described him shouting "Allahu akbar", which means "Allah is great" and is a phrase sometimes used by jihadists during attacks. The Islamic State has claimed responsibility. CGTN's Elena Casas has more from Paris.