Moscow's UN envoy says he "cannot exclude" the possibility of a war if the US launches military action in Syria. Also, the alleged kidnapping of a Dubai princess, and why some patients' cancers are more deadly than others, despite appearing identical.
The US president, who said on Wednesday that missiles were "coming", has now tweeted that he "never said when". Also: inspectors back UK in spy poisoning row and baby born in China four years after parents' death.
The US military is ready to 'provide options' if appropriate but it is still looking into the suspected chemical attack in Syria.
Also, US House Speaker Paul Ryan will not stand for re-election, Bangladesh abolishes job quotas for government posts after protests, and Dutch villagers are not happy about a new singing road.
Senior Russian figures threaten to respond to any attacks by the US in Syria.
Also, hundreds killed as military plane crashes in Algeria, new book says Israeli military made ten failed attempts to kill Yasser Arafat, Soweto hosts memorial service for Winnie Mandela, and fossils reveal how giant sea-reptiles once roamed off English coast.
Facebook's Mark Zuckerberg was answering questions in the wake of a data collection scandal. Also: Russia vetoes UN bid to set up Syria chemical weapons probe and scientists say Lionel Messi's goals make Barcelona shake.
He said the US was getting 'clarity' on who was responsible for the incident in Douma. Also: Yulia Skripal, the poisoned daughter of Russian ex-spy Sergei, has been discharged from hospital, and the first Arab Fashion Week is getting underway in the Saudi capital, Riyadh.