Cordons have been removed after British Army bomb-disposal units were called out to a street in Hulme, with fears growing of another attack.
Local police originally reported they were attending a major incident at a college in Trafford, before clarifying it was a street in Hulme.
Several roads were closed as police assessed the situation - Mancunian Way, Limby Street and Jackson Street.
They were concerned about a "possible suspicious package", they said in a statement.
Police have since lifted the cordons and say the area is safe.
Meanwhile, it has emerged that UK security services were warned multiple times about the Manchester bomber - but failed to take action to stop his attack.
Salman Abedi was reported to the authorities at least five times by people concerned about his extremist views, The Telegraph reports.
Abedi reportedly told his friends that "being a suicide bomber was okay", leading them to contact the Government's anti-terrorism hotline.
Abedi had been banned from Didsbury Mosque because of his views.
"People in the community expressed concerns about the way this man was behaving and reported it in the right way using the right channels," Mohammed Shafiq, chief executive of the Ramadhan Foundation, told The Telegraph.
US anti-terrorism sources say that Abedi's own family contacted the government, concerned he was "dangerous".
Abedi's father, Ramadan Abedi, was a member of the militant Libyan Islamic Fighting Group, and his brother has been arrested by the Libyans who suspect him of knowing about the Manchester attack in advance.