Police staged a "very big operation" to tackle drug gangs on the Castellane estate on Monday, Cazeneuve told BFMTV.
Drug trafficking leads to other "illegal activities that seriously threaten public order", Cazeneuve said, adding "I'm particularly thinking of terrorist activities."
Public prosecutor Brice Robin confirmed that there had been 20-25 arrests and described Castellane, which is home to about 7,000 people, as a cannabis "supermarket" that has a daily turnover of 40-50,000 euros.
Automatic gunfire was heard on the estate shortly before a visit by Prime Minister Manuel Valls, where he was to hail a drop in the crime rate there, in February.
Subsequent raids brought to light seven Kalashnikovs, two revolvers, body armour and several kilos of drugs.
Investigators believe the shooting was part of a turf war.
In May a police anti-drugs operation on another Marseille estate led to 20 arrests.