Mass graves in Mariupol, Information war in Mali, Covid-19 in China, UK 'partygate' probe

Mass graves dug by Russian forces have been discovered in the Ukrainian city of Mariupol. The city's mayor says there are at least 20,000 dead but the real figure is expected to be much higher. Over in Mali, an information war is underway, as France says Wagner mercenaries have faked a "French atrocity" in Gossi. Plus, Covid-19 comes full circle in China, where the impact of the country's strict zero Covid policy is now under scrutiny. Finally, did British PM Boris Johnson lie to parliament over "partygate"?