Thirteen French troops killed in Mali operation against militants

French and Malian soldiers on patrol in Mali.

Thirteen French soldiers fighting jihadists in Mali were killed in an accident between two helicopters, the French presidency said on Tuesday, the single biggest loss of French troops in combat in the region since intervening there in 2013.

France has more than 4,500 troops countering Islamist insurgencies in the Sahel region, where violence by militants linked to al Qaeda and Islamic State in the sparely-populated area has proliferated in recent years.