Twitter Inc will begin placing warning notices in front of some misleading content regarding the conflict in Ukraine and limit the spread of claims debunked by humanitarian groups or other credible sources, the social media company said on Thursday. The step-up against misinformation around Russia’s invasion of Ukraine, which Moscow calls a “special military operation,” is part of a new policy that outlines how Twitter will approach misinformation during crises. Social media platforms have faced increasing scrutiny over how they determine and handle misinformation. Twitter has agreed to sell i…