Russia observed a day of mourning after 137 people were killed on Friday in an attack at a packed concert venue in Moscow. President Vladimir Putin declared a national day of mourning yesterday after pledging to track down and punish all those behind the attack.

Moscow’s Basmanny district court has ruled that the first suspect in the concert hall attack should be put into custody for two months pending trial. Russian authorities have said 11 people have been detained, including four gunmen who fled the concert hall and made their way to the Bryansk region, about 340 km southwest of Moscow. Islamic State terrorist group says, it was behind the attack.