Russia has 'unleashed chemical weapons on Mariupol' with Ukrainian troops reporting they are suffering breathing issues and dizziness - as the besieged port city's mayor reveals more than 10,000 civilians have died in the conflict so far. The unidentified agent is said to have been dropped on the city from a Russian drone, according to unverified reports from the city's Azov regiment. Details of the assault, via the Telegram messaging app, say a 'poisonous substance of unknown origin' has led to the city's defenders suffering from symptoms including breathing issues, 'respiratory failure' and 'vestibulo-atactic syndrome'. The alleged attack came just...