Police confirmed 22 people are dead and 50 injured following the blasts at around 10.25pm BST.
British Transport Police said the explosion occurred "within the foyer area of the stadium", the BBC reports.
Law enforcement officials in the U.K. suspect the bombing was the work of a suicide bomber.
According to NBC News, U.S. officials were briefed by authorities in the U.K. that forensic evidence and a body had been identified at the site of the bombing.
A male on the scene has been identified as the probable bomber, CNN reports.
According to CBS News, the alleged bomber traveled to the arena via train and detonated the bomb as people were leaving.
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A version of this article originally appeared on marie claire