British Prime Minister Theresa May said the attack that killed 22 people in Manchester on Monday evening was "among the worst terrorism we have experienced in the United Kingdom," adding that police believed they knew the identity of the suicide bomber.

The man behind the explosion that shook the Manchester Arena following an Ariana Grande concert, aimed to cause "maximum carnage" by detonating his bomb outside one of the exits, May said. She condemned the "cold calculation" shown by the targeting of children and young people.

Read: World leaders condemn Manchester attack

"All acts of terrorism are cowardy attacks on the innocent people, but this attack stands out for its appalling sick cowardice," the prime minister said.



May paid tribute to the response by emergency services, as well as to members of the public who helped look after those caught up in the attack.

"While we experienced the worst of humanity in Manchester last night, we also saw the best," the prime minister said.

Read: Manchester and the world show solidarity with concert attack victims

May said that a number of those being treated in hospital were suffering from "life-threatening injuries."

Britain's Queen Elizabeth expressed her deepest sympathy for those affected by the attack, which she described as an "act of barbarity."

"The whole nation has been shocked by the death and injury in Manchester last night of so many people, adults and children, who had just been enjoying a concert," said the queen in a statement.

Read: From Madrid to Manchester - a timeline of terror in Europe

Earlier, opposition Labour leader Jeremy Corbyn reacted to the "terrible incident" on Twitter, saying his "thoughts were with all those affected." He later posted a longer statement.

Political leaders spoke on Tuesday and had agreed to suspend their election campaigns "until further notice” following the attacks. National elections are scheduled in Britain for June 8.

Britain's Home Secretary Amber Rudd said the blast in Manchester was "a barbaric attack, deliberately targeting some of the most vulnerable in our society - young people and children out at a pop concert."

Manchester Mayor Andy Burnham made a statement on Tuesday morning, saying the citzens of Manchester had experienced the "darkest of nights" and were "waking up to the most difficult of dawns."

Burnham condemned the "evil act" that took place at the concert, but said "today it will be business as usual, as far as possible, in our great city."

Read: Are Europeans getting used to terror?

The mayor also praised citizens who opened their doors to people fleeing the attack in the immediate aftermath of the explosion. #RoomsForManchester was used on Twitter to provide people with no way of getting home with a place to stay after the explosion.

rc/rt (AP, Reuters)