Heavy fighting at the Thailand / Cambodia border

The Thai military said there were clashes in five border provinces, and three of its soldiers had been killed since hostilities resumed. Cambodia says Thai attacks have killed seven civilians. We explain why this has happened. Also on the programme: in Australia, the law banning children under 16 years from social media has come into effect - one of the most dramatic moves so far by a government against the tech companies that own the platforms. And the revolutionary new cancer treatment, which uses DNA editing, to save the lives of patients with previously incurable blood cancers. (Picture: Thai soldiers on patrol at the border with Cambodia. Credit: Reuters)