Russian President Dmitry Medvedev has sacked several officials after blaming the Domodedovo airport bombing on poor security. In his comments carried on Russian television, Medvedev said those who did not work properly should be punished.Reports say, the dismissals are said to include regional transport chief Andrei Alexeyev and Moscow police deputy head Maj Gen Vladimir Chugunov. Meanwhile, Moscow is holding a day of mourning for the victims of Monday's apparent suicide attack in which 35 people died.