As well as damage to the tributes to the 22 people killed in the bombing in May 2017, there were reports of broken glass and a traffic cone.
The damaged items were subsequently cleaned up and the area was respectfully tidied, GMP said.
The force said relatives of the victims of the arena attack had been contacted regarding the incident.
“The fact that this incident involved damage to tributes to victims of the arena attack is particularly disgusting, and is something that we have zero tolerance for,” said Det Supt Harris.
“I want to reassure the public that we are working hard to establish the circumstances, and I am glad a quick arrest was made.
Police said they were not looking for anyone else in connection with the incident.
Det Supt Harris said enquires were ongoing, and appealed for anyone who witnessed anything or might have information that could assist the investigation to contact the force.
