In the wake of highest threat level in Britain, around 3,800 soldiers would be deployed on streets
Total number of men in custody are four, including brother of alleged attacker Salman Abedi
Libyan-origin Abedi blew himself up after a concert at Manchester Arena on Mon; 22 killed in attack
The attack at Ariana Grade's concert saw 22 people dead and several injured
Nations also use terrorism tactics in other countries to safeguard their own national interest
Security sources are also concerned about the prospect of jihadists returning from Iraq and Syria
After the attack, the 2017 general election campaign has also been paused
Abedi had travelled to Libya within the last 12 months, one of multiple countries he had visite
Fans of city's rival soccer teams Manchester United and Manchester City stood together at protest
The city came together in defiance in the face of the worst kind of cowardice
The threat in UK is at level 4 - indicating that an attack is 'highly likely' or 'severe'
Islamic State terror group claims responsibility, attacker identified