The police staged a mock attack featuring a bomber shouting "Allahu Akbar" drew criticism for racial stereotyping. The mock attack was staged to check the response of emergency services, reported the BBC.
Around 800 volunteers participated in the overnight drill at the Trafford Centre to make it as realistic as possible.
The use of a "Muslim terrorist" during the mock attack was also criticised by the Manchester peace activist Dr Erinma Bell.
"A terrorist can be anyone" and "we need to move away from stereotypes", she was quoted as saying.