used hashtags referring to the blast to post celebratory messages, with some users encouraging similar attacks elsewhere.
Some messages described the attack as an act of revenge in response to airstrikes in Iraq and Syria.
Twitter user Abdul Haqq said it seemed that bombs of the Royal Air Force, which killed children in Mosul and Raqqa had “come back to Manchester”, in reference to the Iraqi and Syrian cities held by IS militants where a United States-led coalition, of which the United Kingdom is a member, is conducting air strikes.
IS supporters reportedly posted messages encouraging each other to carry out “lone wolf ” attacks in the West and shared IS videos threatening the US and Europe.
One user said he hoped IS was responsible for the attack.
“We hope that the perpetrator is one of the soldiers of the caliphate,” he wrote on a channel affiliated to the group hosted by messaging network Telegram.
It was reported that Twitter suspended dozens of accounts, but IS supporters posted messages across Telegram and other secured messaging systems.