Algeria reminded France of a particularly dark chapter of its colonial past during an otherwise celebratory opening ceremony for the Paris Olympics on Friday. Algerian athletes brought red roses on their boat as they paraded for the event, and then tossed them into the river to honour victims of an infamous 1961 police massacre of Algerian protesters in Paris. Some members of the delegation chanted “Long live Algeria!” in Arabic after throwing the flowers. Historians say some 120 protesters were killed and 12,000 were arrested as they demonstrated on October 17, 1961 in support of independence…