IS claims responsibility for Manchester bombing, warns of more attacks

The Islamic State (IS) terrorist group has claimed responsibility for the Manchester bombing, saying a "soldier of the Caliphate" carried out the blast that tore through a crowd of fans at an Ariana Grande pop concert, killing 22 persons, a US terror-tracking organisation said on Tuesday.

SITE Intelligence's director Rita Katz tweeted a message posted by the IS to Telegram claiming it carried out Monday night's bombing with an explosive device planted at the concert and warned of "more severe" attacks.

"With Allah's Grace and support, a soldier of the Caliphate managed to place explosive devices in the midst of the gatherings of the crusaders in the British city of Manchester," read the claim of responsibility, reported Italian news service AKI.

The devices were detonated in the "shameless concert arena" killing 30 "Crusaders" and injuring 70, the message said.

"It was an attempt to terrorise the unbelievers and in response to their transgressions against the lands of the Muslims," it stated.

"And what comes next will be more severe on the worshippers of the Cross and their allies, by Allah's permission," the message ended.

World leaders including US President Donald Trump, French President Emmanuel Macron, and Palestinian Authority President Mahmoud Abbas have expressed outrage over the attack.

The 22-member Arab League and Muslim nations Iran and Turkey also condemned the blast.

IS supporters have exalted the attack and have used the encrypted Telegram messaging service to re-circulate videos threatening the UK and the West, Katz said in an earlier tweet.

Islamic State supporters celebrated the attack on the social media as a victory against "the crusaders" of the West.

In one video an English-speaking supporter of ISIL held up a home-made sign with the word "Manchester" and the date of the attack.

"This is only the beginning. The lions of Islamic State of Iraq and Sham are beginning to attack all the crusaders," a masked man said in the short video.

Other ISIL supporters said the attack was revenge for Britain's involvement in the bombing campaign against IS in Iraq and Syria. "It seems that the bombs of the British air force over children of Mosul and Raqqa has just come back to Manchester," wrote one user.