Ukraine conflict: Russia besieges key cities

Russia's attack on Ukraine moves into a second week - in Mariupol, a strategic port near the Russian border, people are trapped by intense shelling. We'll talk to the city's deputy mayor. Also, as the International Criminal Court starts gathering evidence of possible war crimes, we'll look at Russia's use of prohibited weapons; and as Kherson becomes the first Ukrainian city to fall to the Russians, we'll hear from a young woman there.