1. As martial law takes effect, young Ukrainians urge: "Keep calm"A small group of young Ukrainian students pose with 'keep calm' signs in the capital Kiev to encourage residents 'not to panic' after Ukraine's president signed an act imposing martial law in border regions, amid mounting tensions over Russia’s seizure of Ukrainian ships.2. US indicts Iranians for crippling ransomware spreeThe United States on Wednesday indicted two Iranians for launching a major ransomware cyber attack known as "SamSam" that wreaked havoc on hospitals, schools, companies and government agencies over a 34-month period.3. William and Kate pay tribute to victims of Leicester helicopter crashThe Duke and Duchess of Cambridge have paid tribute to the five people killed in a helicopter crash at Leicester City's ground, leaving a floral memento in their memory.4. Israel unveils rare and ancient maskThe Israel Antiquities Authority unveils what it says is a rare 9 000-year-old stone mask linked to the beginnings of agricultural society.5. Get your hands on boob bread in JapanGrab yourself a handful of the most voluptuous bread you've ever seen at the Kuppel bakery in Tokyo, where a Japanese baker specialises in breast-shaped buns.