Three teenage boys have been arrested on suspicion of GBH after a 16-year-old boy was stabbed in the chest in the Arndale centre.
A mass brawl between two groups of teenagers broke out in the shopping centre on a Friday night last month.
The youngsters were seen fighting at the entrance to the Next store and a 16-year-old boy was stabbed to the chest.
Now six boys have been arrested in connection with the incident.
Earlier this month, boys aged 14, 16 and 17, were arrested on suspicion of grievous bodily harm, also known as section 18 assault, and violent disorder, and have since been released on bail.
GMP said another three boys, also aged 14, 16 and 17, were arrested on suspicion of the same offences and bailed.
Anyone with information is being asked to come forward.
A GMP spokesperson said: "We've arrested a further three teenage boys on suspicion of section 18 assault and violent disorder following an incident on the 28 January, where a teenager was seriously assaulted by a group of males in the Arndale Centre just after 7.20pm.
"The boys aged 14,16 and 17 have been bailed pending further enquiries. The three boys originally arrested have also been bailed.
"The arrests follow extensive enquiries conducted by GMPs Operation Valiant team and the City of Manchester CID.
"Officers are continuing to appeal for information and anyone with footage from the incident should contact detectives on 0161 856 4409 quoting incident 2488 of 28/01/2022.
"Details can also be passed anonymously to the independent charity Crimestoppers on 0800 555 111."