On Thursday afternoon, the 21-year-old leader of one of the two main factions in the conflict was remanded in custody, according to the Sydsvenskan newspaper.
The man is being held on suspicion of weapons offences after he was stopped on a city street on Thursday afternoon and found to be carrying a loaded gun and wearing a bullet-proof vest.
The arrest is being viewed as a success for Operation Targa, the Malmö city and county police forces' coordinated response to the bitter gang feud.
Thursday's arrest came on the heels of the arrests on Wednesday of four people suspected of fraud.
Police said the four were arrested as they attempted to purchase goods using invalid credit cards.
Two of those detained, a pair of brothers aged 24 and 26, are thought to be leading figures in a rival faction to that headed by the 21-year-old.
The brothers are suspected of being behind the attempted murder of a 22-year-old man in Malmö in August, Skånska Dagbladet reports.
A day after the murder attempt, a bomb exploded outside a restaurant in Lund believed by police to be owned by the brothers.