FRANCE faced mounting calls from rights groups yesterday to open an investigation into an airstrike by its forces in Mali that a United Nations probe said killed 19 civilians at a wedding party. U.N. investigators published a report on Tuesday about the January 3 strike, concluding that it killed 19 civilians and three armed men near the central Mali village of Bounti. France, which has more than 5,000 troops in Mali and neighbouring West African countries to battle militants linked to al Qaeda and Islamic State, rejected the conclusions, saying it hit Islamist militants only. Domestic and international advocacy groups,…