▁its ▁previous ▁level ▁of ▁severe . ▁In ▁the ▁after math ▁of ▁the ▁attack ▁Operation ▁Tem per er ▁was ▁activ ated ▁for ▁the ▁first ▁time , ▁allowing ▁up ▁to ▁ 5 , 0 0 0 ▁soldiers ▁to ▁rein force ▁armed ▁police ▁in ▁protect ing ▁parts ▁of ▁the ▁country . ▁T ours ▁of ▁the ▁H ouses ▁of ▁Parliament ▁and ▁the ▁Ch anging ▁of ▁the ▁Guard ▁ceremony ▁at ▁Buck ingham ▁Palace ▁were ▁cancel led ▁on ▁ 2 4 ▁May , ▁and ▁troops ▁were ▁deployed ▁to ▁guard ▁government ▁buildings ▁in ▁London . ▁ ▁On ▁ 2 3 ▁May , ▁the ▁Islam ic ▁State ▁of ▁Ira q ▁and ▁the ▁Lev ant , ▁via ▁the ▁Nash ir ▁Tele gram ▁channel , ▁claimed ▁the ▁attack ▁was ▁carried ▁out ▁by ▁" a ▁soldier ▁of ▁the ▁Kh il af ah ". ▁The ▁message ▁called ▁the ▁attack ▁" an ▁ende avor ▁to ▁terror ize ▁the ▁m ush rik in , ▁and ▁in ▁response ▁to ▁their ▁trans gress ions ▁against ▁the ▁lands ▁of ▁the ▁Muslim s ." ▁Ab edi ' s ▁sister ▁said ▁that ▁he ▁was ▁motiv ated ▁by ▁reven ge ▁for ▁Muslim ▁children ▁killed ▁by ▁American ▁a irst rik es ▁in ▁Sy ria . ▁ ▁The ▁Arena ▁remained ▁closed ▁until ▁September ▁ 2 0 1 7 , ▁with ▁scheduled ▁concert s ▁either ▁cancel led ▁or ▁moved ▁to ▁other ▁ven ues . ▁It ▁re open ed ▁on ▁ 9 ▁September , ▁with ▁a ▁benefit ▁concert ▁featuring ▁No el ▁Gall ag her ▁and ▁other ▁acts ▁associated ▁with ▁North ▁West ▁England . ▁ ▁May ▁announced ▁an