- Video report by ITV News Correspondent Geraint Vincent
The decision to raise the threat level in the UK to 'critical' on Tuesday evening following the Manchester bombing has had far-reaching consequences across the country.
The activation of Operation Temperer by the government has resulted in the deployment of 3,800 troops to support the police in their security operations.
The plan means soldiers could be deployed to support police at major events such as the FA Cup final at Wembley on Saturday or the Champions League final in Cardiff on June 3.
Chelsea football club, meanwhile, has decided to cancel its much-anticipated Premier League victory parade through the streets of west London on Sunday.
US singer Ariana Grande, who was performing at Manchester Arena on the night of the suicide bombing, has cancelled the European leg of her tour, including two shows at London's O2 Arena later this week.
New CCTV of the Manchester bomber Salman Abedi has been released by police.
The younger brother of the Manchester bomber has said Salman Abedi was radicalised online in Britain.