Commissioner of the Metropolitan Police Service, Cressida Dick, said:
“This is an utterly appalling attack. My thoughts are with the people of Manchester as they try to come to terms with the horrific events that took place in their city last night. Our colleagues from Greater Manchester Police and their emergency services showed huge bravery as they ran towards the confusion and danger.
“We are providing every possible support through the counter terrorism network as investigators work tirelessly to understand what has happened.
“Here in the Capital we put extra police officers on duty as Londoners started their journeys into work. This will continue for as long as it is needed, and the mix of armed and unarmed officers are there to reassure.
“Looking ahead to the weekend - a normal busy and vibrant weekend in our city - we are working with all those planning events to make sure we are doing all we can.
“Terrorists seek to spread fear and undermine our way of life. We must work together to stop that from happening. If you have suspicions, tell us; if you see something that concerns you, report it. Together we can protect London.”