Hours afterwards Russia's FSB security service announced it had killed a four-strong "sabotage group" trying to enter the Russian border region of Bryansk from Ukraine armed with improvised explosive devices and German-made submachine guns.The Ukrainian air force spokesman said satellite imagery of the airfield would soon reveal the full damage from Monday's attack, adding that earlier blasts had damaged aircraft at the base.The Engels air base has been repeatedly used by Russia to carry out missile strikes on various targets in Ukraine since Moscow launched its full-scale invasion on 24 February.Separately on Monday, Ukraine's foreign ministry demanded Russia's removal as one of five permanent members of the United Nations Security Council and called for its exclusion from the UN "as a whole".Ukraine accuses Russia of abusing the veto power given to each council member, citing examples of Moscow blocking resolutions on the Syria war and the downing of Malaysia Airlines flight MH17 in Ukraine."