Scottish Labour leader Kezia Dugdale said:
“This is a barbaric and sickening attack, targeted at young and vulnerable people enjoying a night at a concert.
It is a heartbreaking moment for our country, and our thoughts are with the families and friends of those who have lost their lives and with those who are injured.
Across the UK we are today grieving for the people of Manchester. I pay tribute to the dedication of the brave emergency service workers who ran into danger.
We have all been moved by the actions of ordinary people who opened their doors, cared for scared youngsters, provided transport to concert-goers, and are giving blood at donor banks to help those injured. This great city is today demonstrating to the world the true spirit of Manchester.
As a mark of respect, Scottish Labour will be suspending all General Election campaigning today.”