Russia is observing a day of mourning after at least 133 people were killed on Friday evening in an attack at a packed concert venue in Moscow. Flags are flying at half mast, many events have been cancelled and TV channels have updated their
schedules.
More than 140 people were also injured when gunmen entered the Crocus City Hall, firing indiscriminately before setting it on fire. The Islamic State group says it was behind the attack.